I do agree that an option on graphics cards would be helpful.
The only way of getting that at the moment is the Mac Pro Tower unit which is a *lot* of money.
The problem is that some of the stability comes from the platform being made of a small selection of very specific components. If you could throw anything in I'd imagine PC type problems would surface.
It's difficult as the Mac will never be a real force in terms of being a gaming platform without better graphics cards but the only people who need those cards are the gamers. So it's a gaming specific issue and until Apple realise that gaming is an important part of a consumer computer I doubt it will change.
As long as Steve Jobs is the big cheese you won't be able to open up and mess around and change components in your machine. He has always viewed computers as appliances that users should not have (or even be able) to mess with. The original Apple II (designed by Steve Wozniak) had loads of expansion slots as it was for the early computer enthusiasts to mess with but the first Macintosh (a project masterminded by Steve Jobs not Wozniak) with it's graphic user interface was devoid of any form of expansion slot or or anything.
At least with the high resale values of Macs you can sell your computer every couple of years and only have to cough up about £200-£300 or so to get the latest model which isn't bad financially. That's what I do.
For example my late G5 20" iMac is just over 2 years old and is worth about £550 on Ebay. A new 20" iMac is £799.
So I could sell it and just cough up £250 and have the latest machine. (which I may do actually).
So in real terms it only costs me £125 a year to keep up to date as a Mac user once I've made that initial investment.
