Hmm, I think that would be a difficult thing to do. The first thing that I foresee as a problem is that there will still be business savvy physicians that, if maintaining a viable private practice is possible, would be able to do so. Medical practices aren't like large corporations in that a single physician with minimal staff can oversee its entire operation, and the finances would be far more straight forward than for a larger corporation - thus limiting the need for a consultant.
Haha, actually, even in large corporations, internal affairs can usually solve most of the company's problems. Management/strategy consulting is about as murky as it gets when it comes to efficacious results and proposals. My buddy at BCG says his boss always tells their analysts that the best thing you can do after 6 months of working on a project is to rehash what the client tells you on the first day, and if the numbers don't fit, make them fit.
An even bigger problem that in such an economic milieu for medicine, practices will be run very lean. Physicians will be very reluctant to add to their operating costs (this is true even during good times) in order to hire an advisor. Even if there are a few physicians out there willing to pay for consulting services, i still don't see a big enough market to sustain an actual consulting firm. (maybe a small 2-3 man group is possible)
Also, a big part of running a success practice is growth of patient load, which will be HIGHLY variable depending on location. The business model for a rural practice would be far different from one in a supersaturated market in an urban setting. And even similarly sized markets in different states would have very different needs. It would be extremely difficult for consultants to become well versed enough in these nuances to be able to provide long term significant value adds to the client.
Private practice consulting can still be a viable idea, depending on the landscape of healthcare. Those are just a few issues that come to mind without deeper analysis.