Does anybody here know what happened to MPC and if there is any chance to see a new version of it again?

Why not? I can't believe that MPC project is dead.

But at the same time, MPC is very complete and almost perfect.

Even without an update in such a long time, it's still a better player than most out there, and you rarely see bugs or complaints. Proof that good software doesn't need to be updated monthly or weekly to stay relevant.

No, gabest simply doesn't have the time to work on it anymore due to his real life job. I think if he doesn't work on it for a while, someone will pick it up like what has happened to ffdshow. In fact, it might have already happened, see http://forum.doom9.org/showthread.php?t=123537

MPC is a great player but for some reason during DVD playback it has very high CPU usage on my computer so the video is jerky. Maybe due to the lack of hardware acceleration...

I get that too, and it seems to be related to the AC3 audio codec.

If I play a standard DVD with DD 5.1 / AC3 audio through PowerDVD, my CPU utilization is around 20 to 25%, with the video being fullscreen on my monitor.

However, if I play the same DVD through MPC, my CPU utilization skyrockets to 90% or more and I get that jerky video you talked about.

Same thing if I use MPC to play XviD AVI files. If the AVI files are encoded with say, 192 kbps MP3 stereo audio, then MPC plays them back with low CPU utilization.

However, if the AVI files are encoded with 5.1 AC3 audio, then the CPU utilization skyrockets again to 90% or more.

It doesn't really matter the video codec the AVI files use. It can be standard MPEG-1 320x240 all the way up to H.264 1280x720 (HDTV quality) and that has little effect (compared to the AC3 codec) on CPU utilization for me.

Whatever MPC does with AC3 audio, it doesn't seem to take advantage of any hardware acceleration the way PowerDVD does with the same DVDs and other AC3 audio-encoded files.