You will have a very nice rig. About the only thing I can suggest is to make sure you get the right front derailleur. There are a bunch of them- TP/TS (top pull, top swing), well I was gonna list more but it's a long list, would be easier to link to an example:

Some der's

You will want to look at the specs for your bike to be sure. Also, it's a little pricey, but I recommend getting the XTR cassette. It's part titanium, and has lots more weight saving holes milled into it than the XT and IMO it's worth the extra cash. Good luck with your bike. Oh, and another thing, you will need a few special tools to do this, you might look into getting a bike tool kit, and since you are already thinking of upgrading it sounds like you will need it eventually anyway...