From what has been said during the post-10.8.3 discussion, I believe that ScratchSF's guidelines are the most valuable towards the diagnosis of the problem. I also agree with CSound1 that is a complicated issue. What I would like to see further is a way of trying to isolate the problem(s). What I'd suggest is a kind of a well structured survey, where users can contribute with their experiences and by posting their systems' behaviours and characteristics. Maybe someone with more technical knowledge, who might knows what kind of data are useful, worth to be combined with other or not, who can suggest some testing we should perform and report back, etc. But I believe it has to be well organised, otherwise statistics will not work and safe conclusions will not be able to be drawn.
Before I refer to my latest experience regarding battery life (I have posted here before), I would like to firstly mention that it should be Apple the one who should have dug into it. But either they don't think there is a respectful number of users who need an explanation or they just cannot do something about it, it is at least a weakness and rudeness of theirs for not even excuse their absence. Dear users, however, it will not be the first or last time where central management fails and the peers need to take action.
Back to my experience, i think it feels like the battery had indicated longer life after updating to 10.8.3. It could be my false hope, since I hadn't recorded the pre-10.8.3 measurements under the exact same conditions, so I cannot compare. However, I don't think so (being a false impression), although I had to close every kind of potential to drain battery process, in order to get a maximum of -more or less- 6 hours life and please my eye. By every kind, I mean Wi-Fi, Safari, all. Important to mention that this is happening on a 3.5 year old battery with original capacity of 6500mAh and current max. 5311mAh.
Although, as I mentioned, I cannot really say what has really happened for many reasons. I didn't specifically took the exact same measurements before 10.8.3 or even worse, before updating to 10.8.2 from 10.6.x. I also cannot remember safely, because I rarely use/used the computer unplugged, because of the intensity of the programs I use. Moreover, I am pretty sure that my case, concerning the updating process is rather unique and complicated, but the same probably applies to one user from the others. I haven't been able to perform several kind of tests/settings/installations to check battery behaviour, since I have only one computer and I am depended on it daily.
That I can say for sure, however, is that only after updating to 10.8.2 a 'service battery' warning appeared for first time, had gone while being in 10.8.2 after some SMC reset from what I recall, returned after updating to 10.8.3 (more permanently, with a max capacity around 4200mAh) at some point and going away, by just plugging-unplugging the computer, to come to the current data I mentioned above for several days now. What is right and what's wrong I cannot say. Has my battery really some problem and ML was able to detect it, therefore the lower capacity and the warnings? Does it faulty finds it as damaged and thus the lower battery life issues? Is the specific setup of my system responsible? Did the update process itself affected/damaged the battery (a user has claimed that he's gonna remove the battery every time he's willing to do a major update)?
While checking the battery usage, I noticed that when closing Skype (while idling), for example, the battery usage fell from around 1200 to about 900mAh. Is it a sign that probably some pieces of software are not performing efficiently in 10.8.x? Is this getting more complex by considering some software in some specific mac models? Some users have mentioned though of having done fresh OS install and without having installed any application they noticed the battery problem. Others reverted to Snow Leopard and saw the battery's life recovering. Does these indicate that is obviously a OS issue? I can't remember well, the posts become old and numerous and is hard for someone to look up anymore. Well, there is where the organization of our observations should come into play.
I don't claim that I am not pleased enough by Apple's products and service quality. On the contrary! However, I don't see the reason for which any kind of user should not look forward to perfection. Especially when the pursued 'perfection' is only limited to what is advertised…