otravi_Cooldowns (oCD) is an add on that display your current cooldowns, based on what it finds in the spellbook. The version that currently can be found on the SVN is what I finished on a couple of hours of work. It's far from done, but it's more or less functional for basic use.
It also doesn't have any options at the moment and is in the middle of your screen, enjoy :p.
Q & A
Q: What actionbars does this add on work with?
A: It currently works with: Bongos, DAB and Blizzard.
I like oCD as it's pretty much like Cooldown Timer Bars which I'm maintaining a while now. I was planing to rewrite it in a way similar to yours but had no time. If you could take a peek into CDT and build in a few of the features I would use your addon instead ;).
You will have to include a way to either manually add "groups" or do that in some automatic way to prevent multiple bars showing up when using one spell with others sharing the same cd (e.g. potions if you include items, frost/fire ward for mages and so on).
Also sorting and cascading of the bars is pretty nice and it really helps to get an overview of your cds.