Originally Posted by Sloppy
I have the Intel(R) Core(TM) i3 CPU M 370 @ 2.40GHz in it right now, and the closest comparison is the "Intel Core i7 620M Dual Core (A)" ... but would the "Intel Core i7 820QM Quad Core (C)" still work with everything else I have onboard like the integrated graphics etc?
I'm planning to use the MXM expansion slot with a graphics card but they are kinda hard to find right now
Yep, you wouldn't have any problems there (unless something has drastically changed with the mobile architecture). Upgrading the motherboard wouldn't necessarily be a bad thing...but I'm not sure you'd get the benefits you'd want outta it.
And depending on what you use the machine for, might want to think about a SSD disk too. Get a cheap low space one.
For your MXM question, can you check what version you have? (should be in your bios), this will be your more reliant factor here.