Whayong, we just have running what we really need, as mayor rule of energy saving is just not wasting it. On my side I had shortcutd for making camera key software shortcut but it installs also proxymityd which is run all time if any function of it may be needed, so since I don't need additional shortcuts on proxymity sensor I just disabled a panel of options so I have shortcuts on camera button but proxymityd is always off and it would make 10 percent of cpu usage @500mhz if it have to be running.
Same on you disable things you really doesn't need mostly those you won't use anyway (stupid option of one app may suck energy wastefully). To check what sucks most energy just type powertop in terminal and wait for results - the info would be very detailed but most important is list of processes - if only xserver is substantially different from zero it's perfect because it's the one for display and system interface so even it would be almost zero if screen would be off - else you may want identify other programs which suck energy and consider disabling/removing them or just set power saving options and disable modules you won't use. The second important are hardware modules so you would know if switching between 2G/3G would make important changes and same for wifi etc.
Also be sure to have rational settings on each app - checking email every minute won't make you any happier but sucks battery and network usage. You may also consider limit of number of communicators - just using builtin skype is mostly enough or if you don't use skype disable it logging so your favourite one would work mostly solely. Also you won't use communicators while sleeping so temporary logout overnight.
I got about 1.5 days on not fully rational settings, with skype always on while online and medium usage including some usage of university's wifi while some power kernel energy saving options not worked yet, so you surely can get 48H on rational usage and rational settings without charging now, but also don't mind to charge it if it is trivial to (like the time it laying on your home desk).
Notice some poorly written apps or applets may suck lot of energy while they don't really need them (like refreshing screen of non active application or making some heavy request every second. Check if you have any offending apps or if you don't understand it much put output of powertop on forum and ask for help.
Kernel Power is generally only better for your battery since overclock would only trigger on demand (if set up) and there are some tricks to lower batterry usage on both OC and stock frequncies and they are so good you could have better battery life while having KP and overclock than having both stock kernel and stock frequency limit.

Long things short - just check it and if anything wrong ask for help as mostly other apps are problem mostly ones in early test version or needed to run always in background. If you really think there is some problem exactly in KP don't mind showing it here. People are mostly helpful even if it is false alarm but be polite and remember they can help but won't think instead of you.

EDIT: I were ninjad :P