Today, the public beta for Steam China launched. While the global version of Steam has been available in the country for ages, it's lived in a strange legal limbo due to the country's strict media regulations. Steam China is an effort from Valve and Chinese game publisher Perfect World to make a platform that's compliant with these regulations, and will mean Chinese players have their own servers to play on too. For now, it seems both versions of Steam will coexist in China, though there are still concerns that normal Steam could be blocked down the line.
The store page for Steam China is live now. It's nothing too special - it basically looks like a slightly simplified version of the Steam we're used to. At the moment, it has around 40 games, including Valve's big'uns, Counter-Strike: Global Offensive and Dota 2.
According to the Chinese CS:GO and Dota 2 sites, players will be able to log in to Steam China and both games with their usual Steam details. They'll need to fill in some info if they want to migrate an existing Steam account to Steam China, including autheniticating their real name. The sites say Steam wallet balances won't change, and neither will CS:GO inventories, so players should be able to use those as normal. China has national servers for the games now too. On top of that, a post on Chinese social network Weibo says that connecting an account to Steam China won't lock players out of using international Steam either, and they should be able to switch between the platforms freely.
Other smaller games are available on Steam China as well, including Human: Fall Flat (which is quaintly localised to "Noodle Man"), Dyson Sphere Program, and more. According to a Eurogamer interview with Valve, all of these will have had to obtain a license through the Chinese government's official approval process, which most games on the international version of Steam have not. The process is strict, long-winded and expensive, which has put some Chinese devs off of going through it.
There were concerns that once Steam China launched, normal Steam might be blocked in the country. This is something Chinese developers are worried about in particular: a number of devs who spoke to PC Gamer are concerned about being completely cut off from publishing their games internationally, while players could lose access to thousands upon thousands of games. Right now that doesn't seem to be the case though, as Chinese site Sina reports that they're still able to access both versions of Steam. It's entirely possible the Chinese government could decide to shut down normal Steam without warning, however. Unfortunately, there's no way of knowing when or if it will happen.
More questions about what Steam China will mean for developers and players have yet to be answered. I've reached out to Valve and Perfect World, but haven't received a response yet.