libva hardware encoder (H.264)
For quite a long time now there is Hardware encoding support in libva on linux, which enables the use of the QuickSync features in recent Intel CPU-Integrated GPUs to encode h264(and some other codecs) nearly without any load to the CPU.
It would be very nice if VLC supports libva as encoding backend, the required Intel CPUs are not very uncommon, so a lot of people would profit from this.
On Windows, the same could be achived via Intels Media SDK, but i don't know if their license is compatible with VLC.
There are some examples on how to write a hardware accelerated h264 encoder with libva in libva:
I tried writing a basic encoding-plugin myself, but i did not come up with anything usefull, as i'm not very experienced with video de/encoding. But i think for someone who is common with it, it might not be too hard to implement this, although there is no real documentation on libva.