IMHO in comparison, the only thing that's better on 2.4 kernels is this thing called BVDD. it's somekind of a display driver and it seems that nobody knows where it came from, what exactly it is or who made it (please DO correct me if i'm wrong about this).
You're wrong, see below
the 2.6 series have no video acceleration for the pxa270 series of processors that i know of.
The kernels in OE have a patch that enables the acceleration bit (the colourspace conversion and scaling using overlays.
the pxa270 has 256kb of SRAM inside it that is not used by the 2.6 series. at least it ain't used yet. the problem with it is that you can't fit the whole screen of the Z inside the SRAM (in it's native resolution - 640x480). you can fit about half of that inside that tiny SRAM.
The SRAM bit is not really acceleration in the video jargon, it just makes blitting faster, it does not take away processing for the cpu like the overlay does. You can fit a 640x480 overlay into with with some tricks, like splitting the Y U and V planes. There are patches available for 2.6 to make the SRAM mappable, but they are all pretty much for ancient (e.g. 2.6.11) kernels or broken. For playing videos fast enough the overlay bit is enough, the sram thing comes in usefull for heavy SDL stuff like games. BVDD is the combination of overlay and placing a 320x480 or partial 640x480 framebuffer in SRAM.
as for your c860, there is a library for 2.6 series that handles the ati w100 chip.
In angstrom you don't need that lib, the xserver just exposes a proper Xv interface and we have a prototype of Xv + XvMC working for c7x0 series. That means that media players Just Work instead of needing patches to support libaticore or libw100. If you dislike X we have an mplayer that uses libw100 as well.
