After downloading SuSE 10.1 beta 9 via BitTorrent (Azureus) and burning five new CDROMs, I was able to boot the M685 and see the SATA drive and its partitions. I was then able to fully install Linux on the M685. I have yet to fully test the installation to see if everything works, but everything does seem to work that needs to work. The only portions of the installation that need further testing are audio and video playback and WiFi connectivity.
Installation of SuSE 10.1 beta 9 was wonderfully uneventful. All hardware was detected. I noticed that this time when I selected packages to install I did not wind up with a lot of other dependent packages to install as well. When it came time to set up the video system, I was able to simply and properly configure it to 1680 x 1050 resolution. I attribute this to the nVidia GeForce Go 7800 video card in the M685. My earlier Gateway M680 had an ATi X700 Mobility Radeon, which required the ATi kernel driver be installed just to properly use the 2D display resolution. I don't seem to have 3D hardware acceleration at this time. I strongly suspect the nVidea Linux driver needs to be installed, but lack of 3D hardware support is not a show-stopper.
Even though it's a beta, this installation has been the smoothest ever. No surprises, nothing out of the ordinary. It Just Works. Oh. It was another beta, SuSE 10 Beta 3, that allowed me to get most of the Gateway M680 up and running last August.