Is there really much of a benefit to buying a digital SLR over a high end EVF camera like the Minolta A1 or Canon Pro 1?

Besides the high speed 1D or super megapixel 1Ds, it seems that these cameras are almost identical in performance these days. The only real difference I see is the ability to change lenses, but with Canon using an L-series lens on the Pro 1, and Minolta's A1 with built in IS (and every major company putting very high quality glass on their higher end cameras these days anyway), that doesn't seem to be that big a difference anymore, to me anyway.

Is there anything else that the D-SLRs offer that I'm missing?

This a hot topic on many of the photo forums. The only currently available 8MP camera is the Sony 828. It uses a smaller CCD than the DSLR's. The smaller pixels produce higher noise in many circumstances. The Sony also seems to suffer from noticeable Chromatic Aberration (CA) on some lighting conditions. I would wait for several of the newer cameras to reach retailers before purchasing a camera in this segment.

The EVF is too low a resolution to really be useful for focusing etc. DSLR's can't use EVF's because the mirror blocks the chip from the optical path. EVF and LCD screens lack the number of colors, resolution etc. to be of use to many pro's. The LCD screen is only used to check composition of shots and make rough decisions regarding focus. The histogram is used to determine exposure.

Thanks Jeff!