It’s been the hottest rumor to hit Mac gaming in years, and today Valve made it official; Steam is coming to Mac. Even more surprising? It’s bringing a wealth of new features with it.

“As we transition from entertainment as a product to entertainment as a service, customers and developers need open, high-quality Internet clients,” said Gabe Newell, President of Valve.”The Mac is a great platform for entertainment services.”

“Our Steam partners, who are delivering over a thousand games to 25 million Steam clients, are very excited about adding support for the Mac,” said Jason Holtman, Director of Business Development at Valve. “Steamworks for the Mac supports all of the Steamworks APIs, and we have added a new feature, called Steam Play, which allows customers who purchase the product for the Mac or Windows to play on the other platform free of charge.For example, Steam Play, in combination with the Steam Cloud, allows a gamer playing on their work PC to go home and pick up playing the same game at the same point on their home Mac.We expect most developers and publishers to take advantage of Steam Play.”

“We looked at a variety of methods to get our games onto the Mac and in the end decided to go with native versions rather than emulation,” said John Cook, Director of Steam Development.”The inclusion of WebKit into Steam, and of OpenGL into Source gives us a lot of flexibility in how we move these technologies forward.We are treating the Mac as a tier-1 platform so all of our future games will release simultaneously on Windows, Mac, and the Xbox 360.Updates for the Mac will be available simultaneously with the Windows updates.Furthermore, Mac and Windows players will be part of the same multiplayer universe, sharing servers, lobbies, and so forth.We fully support a heterogeneous mix of servers and clients.The first Mac Steam client will be the new generation currently in beta testing on Windows.”

Not only are Valve bringing Steam to the Mac, they’re bringing it in a big way. Purchasing games once for both Windows and Mac, sharing multiplayer across both platforms, and offering Valve releases and updates simultaneously? There’s no question that they’re jumping into Mac gaming with both feet. Oh – and for all you hardcore gamers, expect to see Valve’s back catalogue of games like Half-Life 2 and Portal to be made playable on the Mac in April.