Yeah. I'm using it now. I downloaded the "Test Download" to my PSP. The video took about 45 seconds to download then I quit the browser and went to the Video menu in XMB. Clicked on the MVG file and just started playing it. I'm off to download and try some more content now.
*edit*
OK, played with it a bit more. This is absolutely fantastic! I downloaded a bunch of the the free ones and it looks great! Now all they need is video that I'm actually interested in buying!