Have you thought about trying out a circular cast bar? Kind like the vista version of the loading indicator instead of the old hour glass.

Looks good. Cast time + spell name text + icon in the center of the class icon and a highlighted spark moving from the bottom to the top of the class icon?

Graphics like this is what I ment. So I agree with this one

I notice you had the health draining the icon of colour from top-bottom, maybe for castbar, it could be an overlay from left-right, with the spellname just above/below the icon. Not sure of how elegant it could be, or how easy it'd be to do, but aside from circling the icon, it's one of the sleekest ways I can imagine.

Probably not nearly as easy as a bar, but you could circle the class icon...

Here's an example:
http://www.wowinterface.com/download...4-GCDRing.html

Something like this.
http://s.wowinterface.com/preview/pvw31531.jpg

Although with a simple texture (solid color) and a lot smaller. and the time can spawn under the icon and (like it is in the screenshot) and the name either with the time or above the icon.

Castbar could be a yellow glow around the class-texture, but that wouldnt include a time, texture nor name of the spell.