It's deductable for your employers, certainly. You would likely have problems doing so.
In any case, before you spend the money, you might want to consider:
1) It's EXPENSIVE!! if you get the full blown version and USELESS if you don't.
2) You get a lot of tools that you probably already have and a lot of versions of their operating systems. This is neat if you're running a test center, but useless for home learning (and you are bound by licence not to use the stuff for anything useful, running your own IIS server outside of a test environment, for example) It's a lot cheaper to buy a student or home use package to learn the nuts and bolts if you want to do that sort of thing.
3) You get to pay them for the privilege of debugging their crap for them.
4) Some things never change: Microsoft Help doesn't

IMO, you're better off spending the money on beer: the hangover is more tangible, and less irritating than MS software.

good luck,
Hugh