I got my crystal ball out, and I DO see you buying another card reader in the future.
Most manufacturers don't update their packaging to reflect larger sizes, but that doesn't mean that that 8GB SD card you buy next year will work on the reader you buy today.

It is safe to assume that SD cards up to 2GB and CF cards up to 4GB will work even if the specs say differently, but it isn't guaranteed. If you dig deep enough, you will be able to find out what format version standard the reader uses.
You should be safe sticking with branded readers, like Sandisk, Transcend, Ultra, Belkin, etc. It is the non-branded, sub-$10 ones that might not work.
I can point you to one of the best readers I have owned, the Transcend TS-RD13. It is small, fast, and has 5 slots, the 5th being for xD flash. The other reader I have is made by Y-E Data ( YD-8V07 ). It is a 3.5" floppy / card reader combo for my PC. While not as fast as the Transcend ( ~30% slower ), it IS firmware upgradable.