I'm also looking for an xbmc alternative.
For me, xbmc just gives too many problems. I'd like to use my raspberry pi for listening to music, photo frame, and playing games through emulator, on an 1920x1080 monitor connected through hdmi. The data is on an HD connected through USB.
I tried raspbmc, but it currently has some problems with external audio (i.e. playing audio outside of xbmc) - I didn't manage to get any emulator to produce any sound.
openelec and darkelec had problems with the slideshow - pictures are displayed with the wrong aspect ratio, and resolution artifacts, same with xbian.
Currently I'm therefore using raspbian, with xbmc frodo rc3. my CPU is always close to 100% - even 10 hours after starting xbmc, doing nothing. (checking CPU with top/htop logging in through ssh)
I tried everything - dds is disable, no rss, I removed all addons, set screensaver to dark.
algorithmdirtyregions=1 or 2 gave horrible artifacts, and did not solve the cpu problem. (which I think means that there is a bug)
nofliptimeout =1000 turned screen dark all the time, and also didn't solve the problem.
In addition I haven't been able to start a program (i.e. emulator/emulatorstation) from xbmc. Advanced Launcher keeps xbmc running in a small screen, and I have a problem with keeping the keyboard input when starting a script from xbmc that kills xbmc. So, I have to exit xbmc to start the emulator, and when I do that, often the xbmc picture remains on top of the framebuffer, so I can not see anything typed. alt-Fx doesn't help.
In short, for me xbmc is too buggy and I'm looking for an alternative. I'll probably try what I had on my previous center - mpd + gpmc on top of X11, with some screensaver for the picture frame.
It would still be nice to have a more integrated solution....