Kind of pointless to speculate. As far as we know, 10.7 doesn't even exist (at the very least, it doesn't have any stated design goals).
Well, we do know it exists. Ars Technica has reported web traffic reporting 10.7 as host OS.
I can force my browser to report 10.8 if I want to, or SuperduperstupendousOS 5015. Now, that's probably not the case -- but again, it hasn't even been announced yet, so I'm not sure why we need a thread to guess the release date.