There's PhilC's Pz3Editor... while it's an external app (windows only), It does just about every kind of poser utility task there is. I'm really surprised that Semidieu's Advanced Shaders doesn't do this but I was just playing around with it in poser and, apparently not.

It's as monkeycloud stated, .mc5 and .mc6 pretty much eliminate the need for Mat pose.

Cage does have a python script that can extract material information from various file types and create Mat Poses...not really too sure about it, though.

Doesn't that old netherworks script work in poser versions past 5?

Creating a mat pose in a text editor is so easy, I'm surprised there isn't at least one script out there that does this and is functional in more recent versions of poser.