Of course very few outside of Apple know for sure at this point, but we don't know how likely this rumor is. Website AppleInsider cites a source with knowledge of the iPad 2 who says that the device will have no port for an SD card.
The new slits along the sides of the iPad 2 cases are rumored to be for the 3G models' SIM card. This sounds a bit strange given that we don't see why anyone would need such a port to be available through a case. It's not something that's used as frequently as the volume controls or the charging port.
Given that Apple has already added SD slots to many of their laptops, we don't see why they wouldn't let their next-gen iPad have one as well. What do you think?