Check this out :

Xten joins the Yahoo! Messenger arsenal: now what? OK, here’s what by ZDNet’s Russell Shaw — Now this is getting real interesting.Late yesterday, Xten Networks, which makes VoIP-enabled softphones, said that Yahoo! has licenced the Xten eyeBeam software development kit to deliver SIP-based VoIP in Yahoo! Messenger.Yahoo! Messenger director (now that sounds like a fun job) Frazier Miller said that the app will be for PC-to-PC calling.Earlier this week if you remember (or even [...]

Well they seem pretty decided to conquer VoIP market.
The only big mistake they can do now is to make a subscription service from the Pc to Pc calls.
That’s the third aquisition this week…..