An update from my earlier post...
Today I made a visit to the Apple Store for some impromptu research.
First, I tried a 13" Air. I disconnected the power and launched a few apps. Battery life started around 5 hours. I surfed the web, played around with Pages and launched iTunes. The projected battery life varied quite dramatically, but didn't fall below 3:30. I do not own an Air so cannot say how good or bad this is.
I then moved to a 17" MBP.
Same routine, disconnected the power and battery life showed 5:15. I launched iTunes and started a video podcast, then Safari, then Aperture and finally Excel. I thought this was a fairly representative array of apps and is less than I would typically have running on my own machine.
Again, the battery life reading seemed to fluctuate wildly, updating perhaps every 5-10 seconds. I don't recall seeing this running SL, it would update, but perhaps only once a minute.
After about 15 minutes of use, the projection had stabilized at... 2:47 with 90% battery remaining. Avoiding unnecessary hyperbole, this is in my view very poor.
I wanted to try another machine, but my better half intervened and I had to go for lunch (!).
The machines in the Apple Store have a pretty controlled load. They don't have Flash and I was unable to install it. I mention this as I was wondering if I had an app on my machine that was contributing to the problem.
I know this is not very scientific. I also don't know the health of the battery in the MBP (I neglected to check), but 5:15 straight off a full charge seemed reasonable, but not exceptional.
If I get a chance, I will go back and try a couple of other machines and report back.
Bottom line, this confirmed in my mind that this is a serious Lion issue.