The worst thing is that hardware accelerated video encoding does NOT seem to work with any video converters apart from Cyberlink MediaEspresso (which sucks imo because it has very limited range of supported video formats. It can't even convert Flac audio embedded into MKV files). I've reported this problem here but noone replied to me at all.
It seems that OpenCL in general does NOT work properly. I can use it with some programs such as GPUcap viewer's OpenCL demo and Neat Image Plugin for Photoshop but can't with others (Photoshop CS6 itself, Winzip).
I really hope AMD will fix this problem in the next Catalyst Release.