I've found 3 switcher/scalers that seem to be a good match for our needs:
Ocean Matrix OMX-7280
Kramer VP 725XL
Analog Way Octo Value Plus
We currently have 2 VGA (actually XGA) and 4 TV analog video inputs, but see outselves going more toward digital and HD in the near fture. We curently have 2 XGA video projectors with their own RGBHV splitter. The larger projector has a DVI input we might want to exploit in the near term.