Valve usually doesn't say anything publicly about their projects until they've reached a fairly advanced phase of development(either very late alpha or beta).

There won't be much official word until they're either making a major marketing push, or are basically done with the entire project.

For example, the OSX port of Steam and the Source engine was announced in March 2010, and was released in May of that year.

Maybe he is not allowed to talk yet. I can't wait for the official client and game, because I think when the games start rolling in, the video driver and other problems in Linux will be fixed faster. Then I could use Linux again. It's sad that I currently can't run Linux reliably because of my dual-graphic card (sandy bridge + ati) notebook :(

What I don't like about the article is how he goes into how "great" or "stunning" and "amazing" it all is without, like you said, any details. I can understand if there are limited things that can be said at this time, but I read enough fluff words on the internet as is without any backing to show for it.