It's not so much the alliances themselves that I find disappointing, it's that you are forced into a particular alliance based on what race you choose. This takes away some of the freedom that makes the Elder Scrolls games great and it's probably going to make playing with friends more difficult too. Plus I'm sure I'm not the only guy out there that wants to play a Wood Elf, without being forced into the Aldmeri Dominion.
I guess at this point I just hope I can still explore Morrowind and Hammerfell.