If Dell ever does actually start shipping Linux on home computers again (we’ve only had about two or three dozen threads over the last couple of years claiming it is any day now, despite nothing but No from mike himself) it will be to match up against Apple. Dell himself has said several times he’d love to provide OSX installed, but since Jobs won’t agree this could be what happens instead.
In any event Dell is not going to get a chance to sell OSX anytime soon and I very much doubt anyone who was going to buy an apple will settle for Linux on Dell. If they wanted Linux on Dell they can do that now (just not with the support Apple provides).