As highlighted in Michael Brown's post, we put a lot of effort into our Linux offerings on our workstations and servers.
On the client side, our efforts are much more behind-the-scenes. We recognize the chicken-and-egg problem though: it has to work before many people will want to buy it; and it won't work unless effort is put into it before people start buying it. So we're cracking the egg, not quite making omelets.
http://www.direct2dell.com/one2one/archive/2006/11/01/3396.aspx