Apple just announced a new version of OSX for the summer, called Mountain Lion. Will iWeb work with ML? Probably no one outside of Apple knows, but it's something to watch out for if, like me, you continue using iWeb.
Good question. The developer preview was released TODAY . Seeing as iLife 11 is compatible with Lion, I would expect so. Of course, you would need to have the option to allow ALL programs (and not just those with the Apple signed code)