A lot of people (myself included) were expecting to see a revamped Mac Mini. Instead, about the most exciting thing was the non-glare screen option for the new 17" Macbook Pro.
If I had to roll out a mini now I'd be of two minds: 1) take the price down so people will buy even in a depressed economy. 2) leave the price on the theory that the cost sensitive will buy horrible low end machines for $100 less anyway. If you choose 1 and the economy starts to rebound you have shot your profits for product lifetime. Maybe it is best to wait and see how the next month or two plays out before committing to an 18 month product cycle.
I doubt they're waiting for yet another iteration.