There have been a couple of brief discussions of this in the Open Thread, but it seems likely to generate more so here's a place for it.
The original paper in Nature about AlphaGo.
Google Asia Pacific blog, where results will be posted. DeepMind's YouTube channel, where the games are being live-streamed.
Discussion on Hacker News after AlphaGo's win of the first game.
If those risk management systems are themselves software, that doesn't really change the overall picture.
If we're talking about "would companies place AI systems in a role where those systems could cost the company lots of money if they malfunctioned", then examples of AI systems having been placed in roles where they cost the company a lot of money have everything to do with the discussion.
It does because the issue is complexity and opaqueness. A simple gatekeeper filter along the lines of
is not an "AI system".