Argh, forgot guilt refresh on this one.
The changelog could be a bit more detailed by adding:

On Friday 07 January 2011 11:29:49 Thomas Renninger wrote:

Before, power:cpu_idle events were very specific X86 Intel mwait events.
This got fixed with previous patches and cpu_idle events are now thrown by
all cpuidle drivers and can be mapped to the corresponding cpuidle state
in /sys.

This patch reads out the corresponding cpuidle name of a cpu_idle event
and uses it in the title line of the chart (c-states Cx in x86, omap2
- DDR self refresh states for various arm archs).

It also reads out the corresponding abbr(eviation) and uses the string
to draw the cpu idle occurences. This needs a short (3 letter) string
to keep the overview in the chart.

All features/fixes this patch includes:
  - Read up cpuidle events from sysfs if available
    and thus make them architecture independent
  - Use (free) green color to display idle events in the chart,
    red is also used by "Blocked IO" event(s)
  - Fix wrong class="rect.cX" to class="cX" idle box svg drawing
    definitions. This fixes up black idle drawings for eog (eye of gnome)
    and firefox (inkscape somehow could handle the broken case).

    Thomas