When Google started its messenger business with its 'Google Talk', it was inevitable for MSN and Yahoo! to look at interoperability across their messengers.
The news now is that they will look towards integrating communication across their platforms by second quarter of 2006. Google has said it had always wanted interoperability across IMs, but Yahoo! and MSN may deny that to Google Talk for some time to come.
In another news today, WSJ reported that Google and Comcast together may bid for a stake in AOL's content and messenger business (leaving out the dialup Internet connectivity business).
When Yahoo! and MSN attempt to tie-up the messenger chatting, they should also explore channelling the voice chat across the two platforms. This will force Google and AOL at least to consider something similar. Skype/E-bay would then have to enter into alliances with one or both of these groups.
The result of such a VoIM federation will have serious consequences for Telecom companies and VoIP companies around the world.
Note that Tata VSNL now owns one of the important and large VoIP player in the world, though India itself is a fairly poor market for VoIP as of now.