I think the answer is an emphatic yes.
Some people might see that as a huge business risk. I say if your business model is that dependent on clever, obfuscated source code tricks, it isn't much of a business model.
Having the source code gives you the ability to fix your own problems-- or even someone else's problems. If you can see the source code, the binary is alive-- it can evolve.
Providing source code is the only answer -- it's a way to say to the customer that if worst comes to worst, they can be their own alternate source. Even Microsoft has demonstrated this by providing Windows Source to certain customers, like large governments, who have the leverage to demand it. And, yes, escrow services should be sufficient for this purpose, but for some reason most customers don't like that approach. Perhaps it's lack of confidence in the long-term viability of the escrow services themselves? Or perhaps lack of faith in their own institutional memory to recall that such escrow arrangements had been made.
There are some nice side benefits of having source code available: the ability to learn from someone else's code, and the possibility of customizing components to suit specific needs, but those are smaller issues. Security is always a concern, but it is only applicable to software that has the potential to elevate the privilege of a user -- something that applies to a relatively small number of software components.
So what about the great closed source vs. open source debate? I'm never one to shy away from controversy, but that's for another time and place. What we did by releasing our software was not open source by any stretch of the imagination. Our source code is licensed to individual developers for their own use -- not for distribution. Does a true open source model make sense for the component world? I don't know. What I do know is that source code availability provides a level of peace of mind for some developers that probably cannot be matched any other way.
We should do away with the pretense of hiding code. Let's not only acknowledge that decompiling .NET code is trivial, let's embrace the power of "view source" by shipping source code along with our binaries.