Interesting idea. Here are a couple of thoughts that come to mind...
First, I assume you would only "self refer" those that are well-insured and should have relatively simple follow-up. The problem with that is that people that meet these criteria would undoubtably have a private physician. You would essentially be stealing pts from the very people you depend upon to take the "self-pay" headaches from you come admission time. Word would quickly get out and not only would you alienate yourself from all the private physicians in town, you might also run afoul of administration since you would be pissing off all the consultants who make money for the hospital.
Another aspect would be that you would have to be careful that you don't bite off more than you can chew. When you see the pt in a follow-up role, you are in essence accepting responsiblity for the further care of the pt should any expected and/or unexpected problems or complications crop up. Not only would you not have the time, inclination, priviledges, and quite honestly, training to admit and mangage these people, you will have also black-balled yourself when it comes to referring these people to the other docs in the community that could and should follow them up.
The last thought I have is that I doubt it would really be financially feasable to do this. Considering clinic space and over-head, I doubt you would come any where close to making the same profit doing this as you would by spending this time working in the ED.
So in the end I would think this would be a bad idea. Just my two cents.