How fast should I expect to lose weight?

I have a 38" stomach and have started working out with alot of crunches and ab centric exercises. I exercise 30 minutes to 2 hours a day. I've stopped drinking soda, and I've been able to control my eating alittle better than in the past (some days I eat about half what I used to, others I heat 3/4's. Depends how bad cravings are). How fast should I expect to see results with this regement?