Java ME: So difficult to install and use on Windows Mobile it's insane. You can try to follow the instructions here if you're bold (or crazy). Really, though, why would you bother?
Flash Lite: Soon to be built-into Windows Mobile 6.1. Not all that powerful... which is annoying, really. Sure you get some video but you also get the “opportunity” to view other flash content on the web, ...like ads with monkeys that you're supposed to hit with a mallet.
Sony Ericsson has decided that these are two horrendous tastes that would taste great together:
On Wednesday, Sony Ericsson plans to announce new technology that lets developers combine Adobe's Flash Lite and Java ME into a single Java application. The combination of the two technologies allows developers to get past shortcomings in each technology, said Ulf Wretling, director of Sony Ericsson Developer World. - PCWorld [via]
Please, SE, keep this abomination off our precious Xperia X1. This plan of yours can only end in tragedy.