Actually, the PS3 client lets you browse streamable movies by category, and add them to your watch instantly queue (which is the list that comes up by default when you start the player).
There does seem to be a bug in the scrolling code. I think it leaks memory, as after you've scrolled through about 60 titles, the animation of moving through the list starts to get a little jerky, and then all of a sudden you'll be back at the start of the list. If that happens, I recommend you scroll to the left next time, as to perhaps met up with where you left off from the other direction.
It is definitely easier to manage one smallish list of what you want to stream on the PC though.
