I went to the Innistrad prerelease both Saturday and Sunday; it looks to be a very interesting set. You can’t often get much of an idea about it from sealed, but having opened quite a few boosters now (12 for the two pre-re’s, and 6 prize boosters) I think I’ve got an idea about what’s going on with it.
Humans (Mostly white, but also in green, with the occasional showing in the other colours) definitely seem to be the strongest type straight out of the gate – I’m assuming the set is going to follow the typical “trilogy” structure, where the scene is set in Act 1, everything goes pear-shaped in Act 2, and all is set right again in Act 3. Following that, I’m thinking that although White and Green (and possibly Black) are the colours to focus on in a triple-ISD draft, the next set will do a lot for Red and Blue and Black.
Have a go at this format; it’s going to be very interesting!