I agree, if they had taken advantage of the fact that their competitors are spending lots of resources on simpler OSs for tablets etc and concentrated on providing the best Power User experience out there and spent the time they spent on Unity building really useful software I think there would be more of a business model for them.
1) Get people to jailbreak their tablets and install it. Fair enough but it will be very niche and more of a novelty, will never reach critical mass to get useful commercial apps. Will probably get picked by Chinese manufacturers who will resell cheap tablets with Ubuntu re-themed to look as much like iOS as possible, probably called iBuntu or something.
2) Make deals with manufacturers and produce mass market tablets, they will have to compete head on with android and I'm not sure what their USP would be here. They would either need 100% android compatibility or would need to magic allot of app developers out of thin air.
3) Go exclusively for niche markets, for example selling to car manufacturers developing bespoke in-car entertainment systems. This would be a whole new business strategy for them and would basically remove the need for the "ubuntu project" as it exists today.
