The thing that baffles me about Apple's approach to iPhone updates is that many of these tweaks and changes are seemingly simple, conceptually speaking. Multiple text recipients shouldn't have taken this long. I'm not complaining, I just don't see why they're drawing it all out so much.
I suppose it could be simply an intentional tactic of Apple. This seems to be the most likely situation, as Apple, as a corporation and business, would have certain things to gain from small periodic updates instead of a couple large ones that addressed tons of issues.
Again, I've really enjoyed my iPhone, but adding media texting and multiple text recipients are among a handful of things that would improve user experience without some earth-shattering change or epic difficulty on the part of the programmers working on the iPhone updates. Corporate tactics aside, it seems that this should have been a quick, easy change within the first couple of months.
At any rate, let's be thankful that Apple keeps the updates rolling out and has paid attention to us iPhone owners.