This post by Phil Wolff at Skype Journal summarizes a couple of key questions I've had with regards to Skype. The answers come straight from interviews done with a couple of Skype executives by ZDNet UK.

It is no surprise that Skype doesn't want to play with other VoIP providers. Because of Skype's insistence on using proprietary protocols, it would require some kind of central server to do the protocol translation between Skype and SIP. Then again, the Skype client itself could talk SIP. No gateway needed there. They would need some sort of SIP registrar in order for other SIP services to locate Skype users, but that would be fairly trivial. Either way, they claim customers aren't demanding this, so it's not on the roadmap.

Given the peer-to-peer nature of Skype's network, mutli party video is gong to be a tough nut to crack, though they claim it's on the roadmap. It's either going to require significant bandwidth for at least one party in the conference-acting as the 'host' of the conference-or it's going to require a central server, in much the way SightSpeed does it. I certainly don't expect Skype's High Quality Video to be usable on a multi party video chat anytime soon.

The question is: when are we going to see multi party video, and will it be worthwhile?