Update: Looks like this was a false alarm.
It appears Dell has quietly started shipping 24.4WHr hour batteries with the Dell Inspiron Mini 9. That wouldn’t be such a big deal if the company hadn’t originally shipped 32WHr batteries. Pretty much all of the review units the company sent to bloggers and journalists before launching the product had the higher capacity batteries, which explains why you may read reviews saying that the netbook gets about 4 hours of battery life while the machine that you purchased only gets about 3 hours.
Oh, and the Dell Inspiron Mini 9 order page says the netbook has a 4 cell, 32WHr battery. So if you happen to get a lower capacity battery you might want to try calling Dell and complaining. Who knows? It might do some good.