really nebula is working in lion... but apple package maker installer is creating issues on permissions in few cases. It's very strange indeed. Since we don't understand the issue (it's very randomic, it happens only sometimes) it's possible we'll change the installer at all. Till that moment we'll not support lion officially. I suggest to test nebula3 free before buying, and if you urge to upgrade your system to contact us if it's not working, maybe replacing files manually it should start working
To be fair Lion is not a new operating system. At work we have some machines at 10.6, some at 10.7 and some at 10.8. I have found the Lion/MtLion machines (whether fresh install or updated from SL) to be more stable than the Snow Leopard ones. So there are reasons to update past the 2009 version of OS X.
The changes between Lion and Mountain Lion seemed benign compared to other major version updates (you can tell when Pro Tools doesn't shit the bed on the new version heh). So the thought of having a production environment at 10.8 doesn't seem blasphemous to me. Unfortunately due to this weird error Nebula can't support Lion+ which I also understand but I'm sure they'd love to figure it out and support Lion.