floydee/Ken,
I read your post and thought you were being a bit optimistic. I eat my thoughts. A quick search of the Sigma lens catalogue here:
http://www.sigma-imaging-uk.com/pdfs/Lens_Brochure.pdf
shows they do lenses for the four-thirds fit used by Olympus.
Look at the lenses listed as "four-thirds" on page 14 of the pdf file I've linked to. Not a huge selection, but a lot more than I expected.
Regards,
Duncan