Canon today introduced the long-rumored 50mp followup to the 5DIII in two forms (the 5DS with AA filter, the 5DSR without). Plenty of upgrades for the 5DIII user shooting stills: DIGIC6, better AF system, the 150k pixel color metering sensor, 1.3x and 1.6x crop modes, and more. We also got a new top end Rebel (T6i) and the previously revealed 11-24mm f/4 lens. Meanwhile, the rest of the world gets an EOS M3 (not in the US), and Canon announced development of a super zoom 1" sensor GX compact. I'm sure they're all great products, but they all represent the same thing: playing to the base.
About the only loyal purchaser the camera makers have left is the replacement buyer. Someone who is either replacing their current camera because it's damaged and too costly to repair, because it's seriously outdated, or because they have a regular schedule of putting money into upgrades every few years. What you don't want to do if at all possible is lose those customers to a competitor. So you play to the base.
Nikon has a high megapixel count camera (D800, then D810) that's drawing raves? We'd better match that. Nikon has a really nice wide angle zoom that's really wide (14-24mm) that draws raves. We'd better match that. Nikon continues to push the high end of their crop sensor consumer line upwards (D80, D90, D7000, D7100, D7200)? We'd better match that. Nikon, Panasonic, and Sony are using 1" sensors? Seems like we'd better do that, too.
What you don't want is to lose any of your current customers to crossover. If your competitor gets a reputation for doing something better, you just might see some of your current crowd leave the building at a time when the building is getting smaller.
In DSLRs there are really only two competitors. Canon and Nikon take something around 90% of the market share, and we're talking about 10m+ cameras last year, though this number is shrinking. Thus, Canon and Nikon are definitely looking at each other. Nikon recently made all those f/4 zooms, something they hadn't done before. Why? Canon was there first with really good, smaller, less expensive zooms than the f/2.8 set. Canon went with Diffractive optics, now Nikon has responded with Phase Fresnel.
At the moment, Canon pushed the 7DII prosumer crop sensor boundary upwards, and Nikon hasn't matched that. But if Nikon wants to play to its base, it will. If it doesn't, it will suffer consequences, as some more D300 owners give up on Nikon and move on.
This is product development at its worst and best simultaneously. Playing to the base is best because it retains customers in your ecosystem. You took time to build that ecosystem, after all, so you want to maximize your returns from it. That means keep current users from leaking, and try to attract new folk to it. But that's also the reason why playing to the base is the worse development possible: it's tougher to do things that might attract new users when you're mostly focused on serving current ones.
Playing to the base is a defensive strategy. Keep the gains you've made. Don't let any customers you caught get away.
But playing to the base doesn't solve the problem that the camera companies really face: catastrophic downward sales trends. New customers aren't appearing. You know why? Because the camera companies aren't making the products that would appeal to new audiences. Especially since those new audiences are used to smartphone style fun, convenience, and simple UI.