Alright, since the cat's now officially out of the bag...
1) The figures will be based on the original RAH character designs
rock). The deal was put in place well before the movie was even officially greenlit. Not sure if SSC/Hasbro will also choose to make figures based on what will surely be a crappy movie. But, rejoice... we're at least getting the "real" G.I. Joe RAH figures.
2) The first 2 (unless this has changed): Cobra Commander, Snake Eyes. There have been several in various stages of production.
3) Expect awesomeness, especially in accessories and detailing of weapons.
This has been a done deal and the figures in the works for a while now, so I'd expect to see something tangible (as in actual figures) shown soon (Toy Fair is no doubt an obvious bet).
Clearly, Hasbro has a ton of respect for Sideshow and what they bring to the 1:6 arena. This is the third partnership they've had (SW, Indy, and now G.I. Joe) but perhaps the most telling since this is actually one of Hasbro's own IPs.