There are, indeed, microsurgical approaches to fusion, although still in the development phase. From what I've read, recovery and results are about the same as traditional fusion. Patient selection seems to be crucial in upping the odds for good outcome, as is usually the case!
I have read about a new procedure using the same as the Microdiscectomy but with 2 viewing holes (instead of 1). Dr. Charles Branch at Wake Forest medical center has a webcast of the procedure. I would guess the fusing time would be the same but the healing of the muscles from not being cut should be alot less, plus the pain should be alot less. Give me any feed back. By the way thanks for the responses so far.