That's a tough question; I've been there. I wouldn't ever give advice but I can tell you my own experience, and hopefully others will share theirs, so that you get a wide variety of responses.
After my undergrad, I moved to the Bay Area and I had a chance to get an MBA at a good school, but I turned it down to work on my own startup. For me, it's actually one of my few regrets because I can see now that it would have actually helped me in my startups later. Doing a startup is like rolling the dice; there's a lot of luck involved, strangely. If I had taken the couple years to get that degree, I think it would have bettered my odds later, and would have been worth it.
Again, that's just a personal anecdote and not intended to convey anything other than my limited perspective. Of course, if you're really sold on the idea, you could take a year off and just see what happens as well. Personally, I've worked in both Silicon Valley and France (the 06 :-). I would take France any second of any day of the week. It's a slice of heaven and nothing less. :-)
