It seems to me that people pick races mainly for their unique unites, and then focus their whole game strategy around these units. There's nothing wrong with this of course, the UUs are spread out pretty well among all the eras, so playing a game focusing with a late UU will be different than a game with a early UU.

Anyway, my idea is to make up a mod that randomely assigns a UU to your race at the beginning of the game, without telling you which one it is. The UU could show up in any era, which means you would not be able to research straight for it starting at the beginning of the game. Of course you would have to deal with something like England using Samurai's, but just use your imagination to deal with that.

Any thoughts?

hmm, nice idea - that system would be cool for a second uu...
maybe i will try to implement such a system in my mod...