I remember there once was a page where they compared all Intel Macs against each other - the RAM, GFX, harddisc and so on. I know it was on apple.com but I can't find it anymore.
on the Mac Mini page, they have links up the top for Whats Inside, On Every Mac and Tech Specs. This isn't on the MacBook page. Apple have never been great with consitancy...
Sorry, i don't know where it is. I remember it being there, but i havent seen it recently.