I never had more fun in a elder scrolls game(or most games really) than I did when I was a werewolf in Bloodmoon. That game nailed the werewolf experience better than anything else that's ever been on the market.. not that there has been many werewolf games to which I can compare it..
Vampires I care a little less, mainly because of how absolutely horrible they were in Oblivion(A spell to svck blood? Really? Massive disappointment) but they are very cool and would be a great addition to the game, especially if they add in a good faction for them and make them "real" vampires.
If they decide not to include becoming a werewolf in Skyrim it's going to be a huge disappointment to me and many others, it would also be pretty silly because of how well they would fit into Skyrim.. I really don't see any reason good or otherwise on why they should not be included other than laziness on the developer's part..
So has there been any information? Thoughts on the subject?