Hi knewman,
Since your Official GMAT Score will be valid for 5 years from the date that you take the Test, there's a potential advantage to studying for the GMAT in the near future (while you're in "School mode"). By taking care of the GMAT now - and 'locking up' a competitive score - you won't have to worry about studying later on (when you're already working a full-time job and juggling other aspects of a busy lifestyle). Of course, this type of plan completely hinges on the idea that you'll be applying to Business School in the next several years, but you appear to be forward-thinking enough to have an idea of what your plans are going to be.
1) Do you know which Schools you plan to apply to?
2) Going forward, how many hours do you think you can consistently study each week?
GMAT assassins aren't born, they're made,
Rich