Don't make it hard to get the Ubuntu PCs. Offer them in retailers like Wal-Mart, CompUSA, OfficeMax, whatever, even if they're just sold on their respective websites.
It's time Dell took a stand. Anyone could pre-install Ubuntu, but be bold and offer it to the mainstream consumer.
Uhh.. this same story just leaked to all the news sites. They are going to offer Ubuntu, and sell systems via resellers in stores. Your idea is going to be reality.