I don't know--there are already too many IM programs as-is. There's AIM, ICQ, MSN, Yahoo, and probably more that I don't know about. I'm glad for the existence of Trillian, as it helps when you can use all four with one interface, but it's not exactly the most perfect software I've ever used.
I'll be glad when Google removes the GUID from its cookies and stops saving emails for eternity.