Valve is respected as one of the Western world's best developers, having created the legendary Half-Life and Portal series. It's never released anything on a Nintendo console though, but there's a chance that could change with Wii U on the horizon.
Joystiq recently asked Valve co-founder and head Gabe Newell what he made of Nintendo's new console, and while his response was completely non-committal it's an indication the company might be ready to investigate Wii U development.
Wii U seems to be a lot more powerful than the previous generation. It sort of fits better into the scalability in terms of graphics performance and CPU performance, so I think it'll be a lot easier for us to fit it into our scalability model.
We can't begin to imagine how phenomenal Portal could be on the Wii U controller. Here's hoping.