yeah, there is an easy way back:
Disable: sudo amdconfig --set-pcs-u32=MCIL,HWUVD_H264Level51Support,0
Enable: sudo amdconfig --set-pcs-u32=MCIL,HWUVD_H264Level51Support,1
Btw. some users could not get this work with a running X. I talked to a gentoo guy yesterday.
So, if /etc/ati/amdpscdb does not enable it at all, please do the following:
sudo service lightdm stop
sudo amdconfig --set-pcs-u32=MCIL,HWUVD_H264Level51Support,1
sudo service lightdm start
Catalyst 12.6 final was released. I could not get it running on either E350 or E450. You get a green unsupported watermark (yeah, could remove this). Worse aticonfig tells you "Unsupported Hardware" and does not do any settings. So I would suggest you waiting for an upgrade, till these things are sorted out. I did not have enough time yesterday night to see what additional files are missing, to workaround this behaviour. I downgraded to 12.6b.