The "shortage" area where they are still hiring overseas nurses are in the NICU field mostly (although I've heard that OR RNs have also been on the shortage list, called, "theatre nurses"). I got my license in 2012 and am hoping to go over sometime next year (although only temporarily).
The trouble is getting permission to work, you need to go through the appropriate immigration channels. There are a few travel companies that help foreign nurses and in my overseas nursing class, we had folks doing NICU, OR, and ER nursing that they were able to be placed and getting a temporary visa doing agency nursing.
Keep in mind that UK nurses are paid about half of what US nurses are (well, metropolitan US nurses), so you won't be making the big $$ doing this, rather more for the experience. The social benefits are obviously much better than the US with 5 weeks of vacay time and free health care etc etc.
There's no harm in getting your license just to have it. The NMC have changed things a little bit in the last year and you now have to do some sort of a residency (although you do get paid). I think this is a good thing because all I had to do was take an essentially 3 day class with online study in between to learn about the NHS. It was definitely worth it for the knowledge, but I wish I had some experience in a hospital too.
If you're in school now, keep track of ALL of your theory and clinical hours (maybe by keeping your syallabi). That's the hardest thing in the application, IMHO, because American nursing programs
don't keep big tabs on this as long as it passes the state BON's requirements.