I still have kernel_task issues, and ccleaner and cleanmymac hasn't helped..it randomly makes the cpu task go to above 250% on the kernel_task, and I haven't been able to get information about what to do other than visit a genius bar (which isn't applicable since I bought it at a retailer). A friend of mine says it has got to do with build up of install files and such, that are cluttering my Lion install, and that I should do a fresh install. I've waited with this, cause I'm hoping the new MBP's will come out shortly, and I'll see if the problem is still there on the new one, after having ported the OS. If not, I'll do a clean install..However, back to the topic: I guess there is need for clean up of the OS X. I can't really take the "you don't have to maintain your mac" seriously. Even just the ram usage, which OS X is supposed to take care of itself, it doesn't. I'll regularly have to open Terminal, and write "purge", hit enter, wait 10 seconds, and then the unused ram is free'd up. When doing the ccleaner thing etc. there where a bunch of useless stuff that got deleted...so I dunno what's what, all I know is I have a system that's not consistent without maintenance. And a system that apparently have the same issues as a windows system: cluttering of files etc. after a year+ heavy use in terms of installing and uninstalling apps etc. makes my OS X as slow and irritating to work with, as when I was once on Windows XP and had to geek it out in reg-edit to make it work smoothly.
(ps. I do demanding tasks such as HD video editing, music productions etc. so I guess I'm not a "standard" user when it comes to performance needs)