Is IM still new?
I first used Trillian at least 7 years ago. Even before the internet took off I recall using Apple Talk to keep in touch with friends in College across campus. I've had multiple occasions when I've sought tech support from a vendor using an IM interface, but I often had the impression that the person I was talking to was IMing with too many other people at the same time because it always took so long for them to reply.
Lately I've been a bit frustrated by facebook's IM feature - all too often I try and chat with someone only to have their status change to offline. Perhaps its just me?
I know people who've used Meebo, but too often the library networks aren't reliable enough for it. I think texting is really a better alternative, as its not as reliant upon someone being on the other end to receive it immediately - but can be a good, quick tool when someone is.