I haven’t heard of any serious compatibility issues. Lots of guys where I work have updated their desktops and nobody has complained. I think anything that works on 7 will work on 8. Really it’s almost the same OS, in the developer edition when you use the hot key to get rid of the tablet interface you wind up with a desktop that’s 7 without a start button.
I’ve got a big, complex application on my laptop now, the Finale music composition program that I’d imagine you’d have to go back to 7 on your 8, if you will, to make run. But who wants to deal with that?
If you’re just using email, a browser and Microsoft Office, I’d guess you could just be current with 8.