I think i can clear up a couple things at least....

As mentioned, G35s are skylines(350 gt) with almost no differences at all. Just becuase it is not a GTR and doesnt have an RB, doesnt mean its not a skyline.

There is an AWD G35x which will be available in less than a month, but here is the kicker, its only on automatic non sport package 4 door ones. I know because i worked at infiniti untill last week.

The new GTR is most likely going to have a TT 3.3 engine in japan and a big (5+ liter) v8 in many other countries including the US and wont be here for a while