Screen sharing works via the Skype video channel, of course, and allows for a complete view of a participant's screen. For now, only a Mac may act as a source, though a Linux or Windows machine can view its screen. File transfer is also possible, though a lot of detail wasn't available on this.
The other major feature, Skype Access, offers WiFi access for a MacBook or MacBook Pro via any Boingo access point. These include McDonald's, hotels like Marriott and Hilton and more than 500 international airports. Skype Access will run you $0.22US (€0.16) per minute using Skype Credits.
While we haven't had a chance to play with it yet (we're a bit distracted by a little trade show today), the pitch from Skype sounds interesting. Let us know if you give this a try.