I recieved an email from Apple Developer Connection saying that attendees would be the first to get their hands on 10.2. I guess that means the actual release for 10.2 will be a week or two later.
I can't see any reason why they would launch any hardware at WWDC, though they might use it as a platform to announce updates in specification (RAM and hard drive space).
And, of course, there'll be plenty of talk about Bluetooth.