[MAJOR UPDATE (16:06 MT): News 8 out of Austin has video of the fireball! I can now state unequivocally that this is not the result of the satellite collision. The meteor is moving far too quickly for that; satellite collision debris would fall at perhaps 10 km/sec max, while incoming meteoroids are moving at 11km/sec at a minimum, and this thing is screaming across the sky at several dozen km/sec (assuming it’s at a typical meteor height of 50 or more km). So I was probably right in the first place, and what we have here is almost certainly a single object, perhaps a meter or two across, and it came from deep space.]
I’m getting reports that an extremely bright fireball was seen in broad daylight over Texas (near San Antonio and Austin) around 11:00 a.m. local time (about an hour ago as I write this). [Update: some fireball reports came in from Kentucky on Friday, but it’s unclear if the KY event is connected, since it was a while back. It’s possible, so I remain agnostic for now.] If you saw anything or find links, please put them in the comments. The more reports we get on this, the more likely astronomers can figure out what this was.
Here’s part of an email I just received:
According to Google Earth, I was approximately at 29 deg 53′14.44″ N and 97 deg 57′32.00″ W when we saw the object. We were traveling NE, and the object was a little further NE of us, and was travelling in a NNE direction. It traveled out of sight quickly, and we were unable to figure out where it went from there.
Reports like that are fantastic; get your position as accurately as you can, say what direction the fireball was moving, and how high in the sky it was. Don’t worry about apparent distance; most fireballs look like they are close enough to touch, but can be dozens of kilometers away.
And just to be clear: it was almost certainly not It is possible this was part of the debris from the satellite collision last week. That should take months or years to work its way down to our atmosphere.
[Updated: There are some official agencies (like the FAA) saying this could be debris from the collision. I tentatively retract what I said earlier and say I might have been wrong. Still, this fireball may have been a random piece of rock, a very small asteroid a meter or two across. We’ll know more soon– as more reports come in, we can track the direction of the debris and test it against possible de-orbit tracks of any debris from the collision. Keep those comments coming!]
[More updates: A physics prof weighs in on this here. Either he or the reporter is a bit confused; Iridium flashes are bright glints from reflected sunlight off of intact Iridium satellites still in orbit around the Earth. If someone saw flashes of light as the fireball came in, it has nothing to do with that! A wrecked iridium wouldn’t make those flashes anymore (Updated update: a news site is repeating this confused description. Sigh.). Also, Waco news is reporting the event as well.]
[Update (12:30 Mountain time): Austin TV stations say they talked to an FAA official who says this might be from the satellite collision.]
[Update 13:04 MT: The Austin Statesman weighs in. Nothing really new, but some interesting info.]
[Update (13:16): Via Twitter, Matt Stiles posted a map image showing where he and a friend saw the fireball.]
[Update (16:30 MT): A lot of tweets were saying an FAA official had confirmed this was from the satellite collision. Now, the International Herald Tribune reports FAA spokesman Roland Herwig says they suspect it’s from the collision. I’ll note, though, that the FAA is not the agency that would know; I’d trust NORAD better. A fireball that bright would be from a big chunk, and they’d have tracked it. However, I really don’t think this was from the satellites; it was moving rapidly (deorbiting space junk tends to move far slower than incoming meteors) and in the wrong direction.]
On Tuesday, February 10, the American civilian communications satellite Iridium 33, launched in 1997, and the defunct Russian military communications satellite Kosmos-2251, launched in 1993, collided over Siberia. Five days after the collision, reports have surfaced that burning debris from the collision has been spotted over several U.S. cities from New Mexico to Kentucky.

Calls to 9-1-1 began to come in to Williamson County, Texas sheriff's office around 12:30 p.m. (CT) that burning debris and fireballs were seen falling from the sky onto parts of Austin, Houston, Waco and San Antonio. Residents reported their homes and windows shaking and large explosions. After a search of several areas, the Williamson county sheriff's office reported that no debris or impact sites were found. Earlier unconfirmed reports had said the debris could have been the result of a small plane exploding. 
Iridium satellite. 
Steve Thornton, a resident in Austin told KEYE-TV that he "saw something burn up in the atmosphere going east to west at 40 degrees in the horizon looking north" which was "about the size of a half moon and as bright as a welders torch".  Other residents reported to KEYE-TV that they saw an "egg-shape with an orange center and bluish outer aura; a silvery-white tail."  Some report the incident lasting about 10 minutes.

On February 13, the National Oceanic and Atmospheric Administration (NOAA) issued an alert following reports of "explosions and earthquakes" along with "flashes in the sky" in Jackson and Louisville, Kentucky. There were no injures and authorities could not locate any damage.

"The Federal Aviation Administration (FAA) reported to local law enforcement on Friday that these events are being caused by falling satellite debris. These pieces of debris have been causing sonic booms, resulting in vibrations felt by some residents, as well as flashes of light across the sky," said the NOAA in a public information statement on February 13. The FAA also warns that the debris could cause damage to aircraft in areas reporting falling debris.

"Aircraft are advised that a potential hazard may occur due to reentry of satellite debris into the Earth's atmosphere. It is critical that all pilots/crew members report any observed falling space debris," said the FAA on February 13. Both the NOAA and FAA alerts are in place until further notice and cover an area from New Mexico to Kentucky.

However, Dr. Marco Ciocca, a professor at Eastern Kentucky University told WKYT in Kentucky it would "be months" before any of the satellite wreckage enters the Earth's atmosphere. "The debris doesn't simply fall out of its orbit. It will either vaporize or stay in orbit for some time before falling into Earth's atmosphere." 

The satellites, both of which weighed in excess of 1,000 pounds, and traveling at approximately 17,500 miles per hour, collided 491 miles above the Earth. Scientists say the explosion caused by the collision was massive. They are still trying to determine just how large the crash was and how the Earth will be affected. The United States Strategic Command of the U.S. Department of Defense office is tracking the debris. The result of plotting analysis will be posted to a public website.