Orthogonal to OP:
One thing to consider is that work experience, even if not entirely necessary for acceptance into a program, will make the MBA much more valuable. Even if it's a couple of summers worth, you'll both bring alot more to the classes and, more importantly, take away much more.
While B-school is, at some level, about mastering a new vocabulary and adding to the rolodex, there are some useful concepts hidden there that prior experience will help you to take advantage of.
I did the MBA way before the MD/PhD and before having much experience (had started a couple SMALL companies in college and grew up in a family business, but went right through from BA to MBA - sort of unusual at the time). As a result, it was harder to discern wheat from chaff during the program. That said, there's not so much to an MBA curriculum that you couldn't just "do it all" and sort it out later (my approach - not smartest, but it was a ton of fun), but it does help to have the context.
Now, having had a business background before coming to med school - talk about a different perspective - but that's a totally different subject...
Good luck!
P