The first set of SDKs have been sent out to some developers.
Lots of rumours including it being both home and mobile, AMD powered and July release date.
Personally I highly doubt a July release date, it's too soon after e3 for any traction to be built and not that far away from now.
The now common Q4 will probably the target.
http://www.mcvuk.com/news/read/ninte...o-devs/0157530