Based simply on the depth chart and the strengths of the team, it seems logical to look at 2009 with glass half empty type expectations, especially if Dixon leaves early which has been discussed.
As for 2008, to me a bowl game is a bowl game, and neither MSU or Ole Miss has reached the level where they should be pissed about going to a bowl, but it is reasonable for some MSU fans to think that this could be a big year based on the schedule. Vandy and UK in the same year is always big, something Ole Miss didnt take advantage of the last few years, and your two rivalry games our on the road (Ole Miss and Bama) and looking over the schedule I don't see but two games that you will be a more than a TD underdog (LSU and UT). The spread should be close for Ga Tech/AU/Bama and I would think most MSU fans would expect/hope for one win out of those three.
To me the wildcard is the loss of Michael Brown, the OL which was a strength for the team last year will have three new starters I believe and Im not sure how dominant they can become, because in some games they were dominant (AU/Bama second half).
If MSU only wins 6 games, I do think based solely on the schedule that would be a disappointment. That would be wins over 3 Non-Conf cupcakes, wins against Vandy/UK and a win over ARK or Ole Miss, with losses against every other team. I think it would be ok to call it a disappointment, of course not enough to fire Croom or anything of the like, but it would be a small step backwards.
I still think 2009 will be a rebuilding year, but one most fans will be able to easily swallow coming off a 7-8 regular win season.