I've got the black macbook (which is now 2 years old! :O)
Almost the same spec, cept I've got 160gb HD and that one has a better graphics chip. Had a PC before that but used big G5's at uni so was used to OSX.
Never regretted moving to it, I bought it originally as I was moving to China and my PC was on its last legs. Only problem I've had is the HD failed a while back, I bought the extended warranty so just took it to he mac store and they replaced it and upgraded it to leopard within a week. I would recommend extended warranty, as they can be expensive to fix otherwise.
I'm still using it now for everything, photo editing, im a freelance designer so use it for that if the company doesn't have a spare iMac / Power Mac, and it does a good job of most things, often have a load of high res tif's open along with InDesign, screen size might be an issue for you, but you get used to it. Also, you can install XP on it anyway, and easily swap and share between both.
You can get more powerful pc laptops for the same money, but I just prefer the ease of use and less time fiddling with it. If your not sure, go to an apple store and hog one for an hour and play with it, chances are you'll get the in house apple geek come and show you round it.
I don't feel the need to upgrade it, and it's 2 years old. Chances are I'll be getting the Pro soon, but only because my lady's iMac is 4 years old and needs replacing soon.
FINAL WORD: PLAY WITH ONE IN THE APPLE STORE AND SEE WHAT YOU THINK