That MPFE component looks very interesting. I found an interesting online presentation (http://www.slideshare.net/altera/remove-the-external-memory-bottleneck-in-your-video-design) which talks about it.
I have a need for priority based arbitration in a video application I am working on as well. Although, the MPFE component seems like it might be overkill for my situation. I really only need two slave ports, one for high priority and one for low priority. I was originally thinking of trying to create my own component for this. Perhaps I should request the reference design from Altera and take a look at it first.
Too bad Altera does not include this functionality as standard in SOPC. There are probably many applications that could benefit from it.