It's hard to measure the real impact of these processes on innovation, because we have no good metric for how much innovation is happening. You can count patents, but as Yashinoff pointed out, the average patent is no great shakes.
You could also argue that the huge amounts of money spent on patent acquisitions (whether by trolls or big industry players) actually promote innovation, because they create a market value for patents in addition to the direct value of the invention. But you could also argue that what's encouraged is just the development of cruddy patents intended to be issued, sold, and ignored.
Everyone involved with the system, I think, agrees that it's kind of screwed up at the moment. The saving grace is that patents *do* expire eventually, and expired patents feed directly into actual productive commerce (look at the generic drug industry; it's not romantic, in a sense it's parasitic on other people's inventions, but it gets a lot of medications to a lot of people at affordable prices).
The good news is that the patent-troll phenomenon is intrinsically a problem that follows the money. The d*g*t*l photo world may need to worry about it, but I don't think the stakes are high enough in film any more for it to be a real issue for us.