Totally agree with BroodWars here. This all really comes down to how you define "risk".
Nintendo risked that their forays into alternate control schemes with the DS and Wii wouldn't catch on with the gaming mainstream. They also put out risky, unproven products like Wii Fit Plus and Wii Music.
Sony has taken several MAJOR gambles this generation, starting with shoving Blu-Ray into the PS3 to give it a $600 price tag. Then you also have the fact that they relied on original IPs for the first two+ years of the PS3's life, then pushed Playstation Home, and then pushed the PSPGo to move into digital distribution.
The major difference is that Nintendo's risks have been "calculated" risks, whereas Sony's risks have been experimental to the point that you say "Ummm...neat concept, but how the hell are they going to make any money with that?"
What I like is that both Sony and Nintendo have taken a lot of chances this generation, and they'll both learn from each other's mistakes and successes. I think that's really what's best for this industry, not whether or not Nintendo or Sony "wins".