I did a small test (since a guy on apple store killed my HD -_-" fortunately I had a time machine backup - thanks apple for providing me a tool for fixing stuff apple "technicians" break):
My data on HDD was gone so I decided to install Snow Leopard and make a comparsion with Lion - guess what? I get exactly the same time running on battery both on SL 10.6.8 and Lion 10.7.2 so I suppose that 10.7.2 fixed battery problems (at least for me).
Also the battery time thingy on the menu bar keeps increasing (after installing lion I got 4hrs while web browsing via WiFi - after a week I can see 8 hours while doing the same thing). Maybe it just has to be "trained"?