The Wii is certainly no slouch. It has been doing amazingly well since its release, and even up until now is selling very well. Last month, it sold more than the PS3 and Xbox 360 with 425,000 sold.
That success is not lost on Valve. He talked about the hardware of all three consoles, and the criticism Nintendo has faced over the Wii's less-than-stellar components as compared to the PS3 or 360. That presents a challenge, he says, but in the same breath mentions that not developing for the Wii is not helping them:
You canít think of it as graphics, CPU, texture bandwith scaling, you have to think of it as more fundamentally, and I think itís more valuable. I think itís more interesting than just graphics chip Ė CPU combination. Itís the machine I have at home. The fact that we donít have anything in development on it even though it represents big opportunities as a whole, itís an obvious hole in our strategy.
The interview also mentions newer technologies like DX10. It's a good read.