Kettle, at the LinuxWorld conference, talked about the virtualization on Linux and the potential value to the market it could bring. In particular, he expressed hope that it would hit $1 billion in licensing revnue within 4 years, which would be tremendous growth given the current size of virtualization alone. Assuming you buy that and the IDC's predictions, that would be at least a 10% share in the “paid” market worldwide.
He also mentioned the potential for it to bring increased protection on an individual user basis, such as applications running inside Vms for specific purposes. This idea has been toyed with before, even by Microsoft. Now, whether or not Dell will put their money where Kevin Kettler's mouth is another story altogether.