Facebook & Google login have been a source of a bit of pain mostly because of the obtuse and confusing documentation from both companies. Chen spent some time writing up tutorials for both Facebook Login & Google Login that should help you get started with applications that use such login options.
Future Of Windows Phone
I've been holding back on writing this before we have further information and can properly asses the situation. However... since MS is taking its time we'd rather discuss the future of Windows Phone once rather than all over the different forums/social and support channels.
As you know we wrote roughly 3 different Windows Phone ports, the first targeted Windows Phone 7.5 (mango) which relied on functionality introduced in that version and immediately killed in 8.0!
We should have taken the hint that MS isn't serious about Windows Phone back then but we made a second attempt for support with a port to Windows Phone 8. This port used the official API's but they weren't very suitable for a tool like Codename One and this performed really badly, it had horrible bugs to boot.
The third attempt which is now live uses Sun's Pisces framework to abstract graphics which is a real hack, it "works" but is pretty limited and still performs poorly.
We were thinking about a complete rewrite on top of DirectX for quite some time, however such an effort would require a huge expense in time and resources on something that none of our enterprise customers considered crucial. A few pro users asked for that (less than 4 if I recall correctly) but that can't justify what is effectively close to a 100K USD expense in time and effort.
For quite a while there were rumors that Windows will feature Android compatibility and MS recently announced just that. We don't yet know if it will work with Codename One but it should be relatively easy to support Windows devices using a compatibility layer such as this and effectively skip a lot of the complexity.
Since this technology isn't out yet and we don't know what will be required from us to be compatible we can't make any guarantees or even assumptions on how/whether this will work. However, this does look like the best way to support Windows Phone and make the port far more maintainable/performant/feature complete.