Possibly you don't see anything about it on here because iMessages is so crappy that everyone gave up on it and reverted back to SMS long ago.
I know... a lot of people still use it!
But for me, iMessage sucked... it was slower, unreliable, and was sending messages to wrong people, not very good at reverting to SMS once I left the WiFi signal... I tried it out because my kids wanted to be able to text me (and me to them... the littlest ones don't have phones yet) from their iPods. But with unlimited SMS on the family phone plan, there's really no point in using an inferior service like iMessage.
It's too bad... The idea ... being able to text from iPods and iPad and iMac is a great idea... Apple just doesn't seem to have all the kinks worked out yet.