I have a top 10 MBA, and I feel as though it was a waste of time. Sure, it can get your foot in the door, but I feel as though focusing on a specialty is going to be more valuable in the long run. The MBA is just too general, even with a concentration in one particular area.

To those of you who said it's a great corporate stepping stone, you're absolutely right. If it gets you a promotion, then by all means pursue it. If, on the other hand, you wish to direct your career toward owning your own business, it's probably going to do little more than look fancy on your business cards.

Not necessarily.  If you decide to run a consulting firm specializing in one of the business fields (management, marketing, finance, etc.), an MBA can be a valuable asset.  It isn't necessarily limited to working in the corporate arena (though it is admittedly much more ideal for such).