Instant Messaging is now dead for me because all the people I used to chat with are now fragmented across 4 or 5 different services. Aside from those who gave up on IM for the same reason I now have to.
You've all literally killed IM. Well done.
Sure, you usually get a common denominator of features between the various networks, but presence and chat usually is enough.
Whatever. Google Voice is a dying product, and I hate them for what they've done, but at least the underlying transport is SMS and a portable phone number -- if I want I can host it myself in Plivo, which I plan on doing soon.