Hmmm, I don't know any Mac app that uses up to 2GB RAM, but if you're gonna use boot camp and dual boot with XP, then go for 2GB if you're going to run FEAR or other heavy games on it.

I'm not sure about Macbooks, but most laptops use 144pin DIMMs, not 168pin, so you need to check carefully before buying extra RAM in the future.

As for superdrive, I dunno, maybe can maybe cannot. Check with Apple. But what azxel said is correct. If you buy no superdrive now, next time can add in a firewire superdrive (or if you're feeling cheap, a superdrive fitted in a firewire case).