By all means, go to medium format if you can afford it, and want to! It's not just the cameras, you have processing issues and equipment, too. Just FYI.
Originally Posted by chaim
If you decide to stick with 35mm, others have suggeted Nikon, and that's hardly arguable. However, you can get another Minolta manual body for not much, and it will use all your lenses and accesories that you had with the SRT. If you shop carefully, there are tons of SRT's out there. Just be patient and wait for a good one. If you want to "upgrade: a bit, I would suggest an XD-11 or X700. You can use your "MC" lenses and still get auto exposure, just not all of the exposure options. Then again, "MD" lenses are hardly rare either.
It all boils down to personal preference. Medium format is a revelation if you've never done it, but it will be a small investment.