I would like to thank everyone for the good words about MAS. We have always been trying to stay on top of the growing needs of our customers and bringing them a powerful, solid and easy-to-work-with system, which could be adapted to work with many different types of site layouts.
vittle and Useless Warrior - I believe MAS can do everything that you were after. Feel free to have a look around
http://www.mansionproductions.com/mas/ and contact us with any specific question or feature that you are interested in but do not find the answer.
Gerco - MAS works with virtually any kind of [video] content. It is just a matter of a player to embed in the video page template. Like GrouchyAdmin correctly said, if you have troubles setting it all by yourselves, we can provide you with the basic code to display a different player based on the format (i.e. WMP for wmv and avi, QuickTime for mov and mpg, Real, FLV etc.). JW FLV seems to be one of the best and affordable players out there, and it does support H.264 if member has Adobe Flash 9.0.98 or later. We can help you set it up in your members areas if you like that, you just have to take care of the player's licensing fee (20 EUR). Or you can choose another one, not a problem.
AJHall - that's was a very good and thoroughful explanation on the security features!
Like you say, "Security is a process". I just wish to add that this process involves many parties - not just the software vendors, but also the hosting company and the webmaster (owner), and it should be taken seriously by all.
Not a big use of a bullet-proof CMS if there are other weak scripts on the same server, or if passwords are not being stored and kept respectfully.
In this regard, we always recommend our MAS customers to make use of the "Limit admin account by list of static IP addresses" feature, to be on the safe side.