Any update on this?
I'm looking for an answer to the same question as kiwi66; it's now three months later and still nothing but silence about virtualizing Lion 10.7 client using Parallels SERVER for Mac (please don't confuse this with regular Parallels for Mac). I understand that Apple's previous EULA for 10.6 and lower legally prevented this, but Apple's EULA for Lion client permits it, so this restriction should be lifted.
What's the holdup?