Alright. If I need to then I can alway upgrade.I would say yes. But im not sure.
At school we use macbooks with 1 gig and it runs photoshop smoothly.
http://docs.info.apple.com/article.html?artnum=107918
That article should help you explain it all.
And if you ever have any swap memory. It's like the old virtual memory from OS 9. But it's only ever used when you have used all of your actual memory and then the hard disc space is being used.