Not a lot!! I also just went into Diagnostics and it's saying WAN interface not configured.
You have set the Operation mode to xDSL modem router mode rather than Wireless router mode haven't you?
Yes, you need to enter firstname.lastname@example.org and BT in password
Sorry, assumed you had already entered that during setup.
If that fails, set the device back to factory defaults in system tools and run through the Quick Setup again.
Keep an eye out for further firmware updates, there is currently a beta test version for G.Inp that is expected to be rolled out shortly.