Must be a problem with their servers - my XDK wont let me in - it can't authenticate.
The windows XDK download link on the main website doesn't work either so they probably need a server reboot or something.
Keep checking, it'll probably kick back into action shortly.
Please restore all !!
Looks like the forum is running on CST (central standard time).
I guess we wont see any fixes for another 3 hours or so. Doesn't look like the XDK has 24 hr support.
It's a shame, I really need to work on my app!
I wonder if a future release might still allow you to work on your local code and do local testing without needing to authenticate.
Twiddling thumbs with fingers crossed...