Not enough to justify the $500-1000 price difference between the 2 if the upgrades are what people are speculating. They have to be able to justify the price difference. Not just a little better, but $500-1000 better. Sorry, but a dedicated graphics card, a bigger monitor, and a little more power doesn't justify it for most people.
I don't see Apple making all of the upgrades some people are thinking. Some, yes, all, no. It is a wish list by many.
it also has a lot more ports, including the express card slot, which IMO is a huge deal...