Concentrate on becoming a well rounded applicant. Whatever you choose to do you're going to have to explain it during your interviews and discuss how it has helped you become a better person/applicant. Concentrate on step 1 and doing some more research.

Don't forget about volunteer activities and leadership positions. Facetime with faculty and getting your name out there is also important.

I have a friend of mine who did an MBA during a year off. I don't think she saw it as a huge benefit when applying for residency, although I doubt anyone was "turned off" by it. There's this whole image that docs are "allergic to money", yet the fact is to maintain a decent practice that has longevity, you need to be financially adept.

Overall, I agree with the above. Your app needs to tell a story. If your MBA contributes to the message you wish to convey to the committee about you (very innovation/business minded, belief in appropriate practice structure, etc..), then awesome. If it looks like you just threw random stuff into your shopping cart to make it seem full...just like everything else, it probably doesn't help as much.

Having recently matched w/ a combined MD/MBA, it can definitely be an advantage if you sell yourself well. My advice would be 1) make sure you can tell a good story about why you got the MBA and 2)to try to find some research project that let you use some of your MBA skills (ie economic analysis or decision modeling) to help show how you will possibly use your MBA in the future. I don't think it will be a huge make or break for you when interview invitations are going out, but it can definitely give you something interesting to talk about on interviews and can really be an asset at that point in the process. Also, there are a number of big time programs out there with current MD/MBA residents, so its not that uncommon. PM me if you want more information on what I did to fit the MBA into my application. Good luck.