Was pretty surprised to see gamemaker on there. I had heard that it didn't play too nice with steam for a while.... perhaps their willingness to fix that, is what helped them out... or Valve helped them out. It makes sense for for either one to happen now that green light is live giving indie games a better chance.
Gmaker is on there pushing their steam support. 3d coat is pushing their Team Fortess 2 export. 3d mark is obvious benchmarking standard. Then theres art rage, a rather inexpensive art app that could relate to various parts of game and game fan art. Their all Valve, Steam or Steam community friendly.
Maybe that is what C2 needs... someway for it to play nice with steam and make games that can be ran in steam... a traditional windows exe
with the support needed without any third party tools to export it. Additionally it would need all the bells and whistles of steam intergration. That would also help grab their attention.
If C2/html5 is the future; then steam is currently the bridge to it. Its time to put a sign on the bridge so people know how to get there.