I'd venture to say OS X is more stable than any Windows OS.
Aside from that, I see a Mac as a great machine if you want to do pretty well what you mentioned. Things like graphics, video editing. Heck, I've seen some feature that makes for easy programming with Java. Yeah, I don't personally have one of the new Macs, but that's what I'd want to get one for. Just a great machine. Pricey yes, but well worth the money in my opinion. The only issue you need to look at is if there's any files you deal with that may have compatibility issues in switching to a Mac. But unlike Windows, OS X does a good job at providing you with options for keeping stuff compatible between OS X and Windows.
My vote: go for the Mac!
