Over the life of the I-Opener, just under 50,000 units were sold. 20,000+ of these units went to hackers. (Data taken from Netpliance's SEC filings) There was a huge community and therefore huge synergy.
In contrast, Virgin only ever made available 10,000 units. A great percentage of these went to non-hackers. Hackers were deterred by the idea of a neat gizmo they couldn't hack for 3 years on end due to the required contract.
Then again, the Virgin hack will proceed much more smoothly based on lessons learned from hacking 5 generations of I-Openers. The couple thousand or so people who will dare to hack a Virgin (and manage to find one, if they don't already have one) will be pleased. The unit takes up much less space than the I-Opener, is shinier, and cuter.
But the IR keyboard is flakey. I suggest a USB keyboard.