We are planning a mostly bicycle (we will use trains for distance travel, but bikes for the rest) trip in Alsace, Mosel, Bavaria, with a brief visit to Zurich (and maybe Luzern) and possibly some biking in Switzerland. I have seen references to biking between Basel and Colmar, France, but nothing from Zurich. Are there decent (without mountains) biking options from Zurich to Colmar/Strasbourg?
Open http://www.veloland.ch/en/routen.cfm, enter as regions Zurich and Basel and combine the different routes (using largely E6).

The ADFC map nr 24 gives you good survey for the possibilities especially est of the Rhein.
Search on amazon "adfc 24"

Absolutely. Switzerland is heaven for cyclists. There are 8 National routes, ( cf poster 1's suggested website) plus hundreds of regionbal ones, with good links.
ONe suggestion would be to cycle from ZUrich to the Rhine at the Rhine falls, then follow the route down the Rhine, through Basel to Colmar.
Or, "INland" you could folow the route through to OLten, then down to Basel. There are map books with detailed notes on all the National routes, but I have found them all so well marked, that I stopped buying the books and just use the free tiny map of the country and routes, that you can get from any of the IH hostels. They have all the hostels marked as well.
Warning: cycling in Switzerland can be addictive - I came for one short cycle ride around Lake Constance, and now I live here :-)