I think you two may have a different issue which I have also noticed. Sometimes all input stops for a few seconds then resumes. With that issue though, the input you typed then quickly catches up after a few seconds.
The issue that was described here by miles is not only longer, but any input during that time is not seen at all. In fact, you can't even activated or deactivate num lock and caps lock. It's like the keyboard is disconnected from the computer. I too am having this issue. It seems like it occurs most often after the computer has been running for a while. Another interesting coincidence is that I also have a macbook pro. Mine is the most recent model (2.2GHz). I'm hoping that this will get fixed as it's really annoying to have to restart to fix it. Granted the keyboard starts working again, but for me it usually ends up stopping again.