Seidio let me know that they have started accepting pre-orders for their upcoming 3500mAh battery for the Bold which will ship Nov 28th. That is more than double the standard 1550mAh standard battery!!! The only downside is that it requires a new back cover that extends the back of the device 5-6mm. The included back cover is rubberized which some people may appreciate and it will still fit into Seidio’s holster since the phone is face in.
Seidio also has a 1650mAh battery that is the same size as the RIM OEM battery but that only adds about 15% from the stock 1550mAh battery.