Here are the official responses from AdStream regarding QuickCut and Linotype regarding FontExplorer X Pro.
AdStream Support – Jamie Davidson (Head of Print and Online)
I’m happy to advise that at this stage adstream have had no reports from our customers of compatibility issues with OSX10.7 and our Quickcut product suite.
Linotype Support – Dejan Grbic
Unfortunately we have no official statement about this issues. We will release FontExplorer X Pro 3.1 very soon, which will contains new Plug-Ins for CS5.5 and some bug fixes for Lion.