In my eyes the "pulseaudio" task is suspicious. It's responsible for all kinds of audio. If you had audio active while you took the screenshot, then there's nothing to worry about.

OTOH if you did not have any audio active, then you might experience a problem that I have from time to time: Pulseaudio consumes 3-8% CPU without playing any audio. This is always preceeded with audio usage of some kind (like opening the media player and closing it) but not with a 100% reproducible pattern.

The workaround for this problem is to reset pulseaudio, by issueing "killall pulseaudio" (from a root shell). The pulseaudio system will then automatically be started again (you will not loose the ability to play audio), but the new incarnation of it notes that there is no audio to play and goes back to 0.1% CPU.

Note that I didn't update my N900 yet, so maybe this advice is not helpful to your problem.