From the Skype PR
"*Costs for using the lite version of Skype:
You will be charged by your mobile operator for local air time and data usage based on the type of calling service and data plan you have purchased. Since the lite version of Skype uses a mobile data connection to sign in to Skype, update your contact list, update presence and send/receive messages, you will be charged by your mobile operator for data usage. You will not incur charges from Skype when you make Skype-to-Skype calls or send instant messages to friends on Skype; however national calling rates apply from your mobile operator due to the use of local air time. Skype will charge its regular very low Skype rates when you call landlines and mobiles using Skype or when you receive calls on your mobile handset from other Skype users or people calling your personal online number."
So...this sounds like iskoot and all the other VoIP for BB clients out there (using both data and voice plans), except it will work over Wi-Fi without requiring voice plan usage - right? That's what it sounds like for the iPhone: "Sign in to Skype from any WiFi zone and reach friends and family free with Skype-to-Skype calls." If voice plan usage is required for Skype-to-Skype on BB, it seems pointless to me.