...or unregister my license on one computer and re-register it on a new computer? I only have a laptop with 4 GB ram right now and I'm planning on buying a new desktop sometime next year.

You can have it installed as many computers as you like. Steam can only run on 1 at a time is the only limit.

Wolfpup is correct, when you get your new computer you just need to log in with your existing Steam account and you'll be able to install the game.

HURRAY! I went and bought it this evening just after I had posted this. Lol. I'll give it a try on my laptop and see if it can handle it. Very good by Bethesda to recognize that people sometimes buy new computers. Hehe.