And in/despite what a few of the others have said Minolta's are awesome cameras and ALL of their lenses are interchangeable regardless of the camera body including the Sony Alpha. The only things to remember is that the older lenses (the non auto focus ones) will require you to shoot in manual mode more often than not. And when used on the Alpha you will get a slight vignetting effect on the edges of your pictures since the lenses were not designed specifically for digital cameras.
I'm confused
Are you sure you can use manual-focus Minolta lenses (in other words the previous generation which had a totally different lens mount) on the Maxxum/Alpha ones? I was under the impression that the spacing differences meant that infinity focus would be impossible without an optical adapter. When I was looking into it, Minolta user websites were mentioning Olympus as the only current system that allows full use of Minolta MD lenses without an optical adapter.
As for the vignetting... why does it matter that the lenses were not specifically designed for digital cameras? The lenses are intended for coverage of a 35x24mm negative which is larger than the Alpha's sensor... so in fact any vignetting should be reduced rather than increased.