must be reinstalled..
err.. why?

The limewire code doesn't change just because you are using a new version of java. (different parts may be used, but it's all there already)

And more than one java version can coexist perfectly fine on one computer. I'm running three in fact. 1.2.2, 1.3.1, and 1.4.0, and switch between them as I see fit.

Pardon me, It just occured to me. You would need to reinstall, so the installed shortcuts point to the new version of java. This didn't occur to me, as I am capable of changing the shortcuts myself