It seems that Dell is going through with this, they will be offering Ubuntu on three specific models:

• Dell E520 Dimension
• Inspiron 1505
• XPS 410

You will have it preloaded with all the necessary productivity software. Also Dell said they will work with hardware providers to increase driver compatability with Ubuntu which is good for the public. Also this is bring some mainstream light on to Ubuntu which hopefully does some more good. They will be installing Ubuntu 7.04 “Fiesty Fawn” on the Dell machines.

Link: Engadget