After Valve's series of teaser images, it's now been revealed that their upcoming sequel Portal 2 will also be coming to the Mac. The above image comes from a series of scans from the latest issue of Gameinformer magazine which carries a cover story about the much anticipated sequel.

CS Nation has gotten some information from the Latest "Gamer Informer" magazine which has started to arrive to subscribers. 

Single Player Details

• Stand alone, full-priced retail release
• GLaDOS and Chell return
• Portal 2 takes place well after the events in Half-Life 2
• Portal 2 takes place hundreds of years after the events in Portal
• The labs are in various stages of decay with plant life taking over many areas of the facility
• The AI cores (seen previously at the end of game cutscene in Portal) have been tasked with rebuilding the facility
• One such core, Wheatley, serves as a preliminary guide at the start of the game
• Wheatley, fed up with his rather limited lifestyle promises to aid Chell in her escape if she helps "him"
• Wheatley will be carried through some of the earliest areas of the game and can be used to open various areas of the lab to bypass obstacles
• Chell encounters GLaDOS rather early on in the game: "Oh, it's you. It's been a long time. How have you been? I've been really busy being dead. You know, after you murdered me? (...) Okay look, we both said a lot of things that you are going to regret. But I think we should put our differences behind us. For science. You monster.
• Chell no longer sports the orange jumpsuit
• "Vital Apparatus Vents" are tubes with strong suction that Chell can use to her advantage. Place one portal at the suction area and another near some debris that needs cleared and a vortex of objects is sucked out of the room through the portal.
• Tractor beams are new and can be used to help Chell reach otherwise unreachable areas
• "Projected bridges" are translucent bridges that can be redirected through portals
• "Paint" has been added and does react to the physics of a portal
• Orange paint rockets Chell at high speeds
• Blue paint acts as a trampoline like substance and can even be used to coat cubes to send them bouncing around
• Aerial Faith Plates act as spring boards to send Chell flying
• Redirection cubes have reflective sides to bounce laser beams at angles
• Weighted Storage Balls
• Due to the state of the facility, GLaDOS is often forced to send you behind the scenes of the test chambers to make your way to the next area
• Erik Wolpaw, Chet Faliszek, and Jay Pinkerton (National Lampoon) are the main writers on Portal 2
• Music will play a bigger role this time around. Players will find new songs throughout the game through various means.
• Jonathan Coulton will be involved

Multiplayer Details

• Separate, full-length co-op campaign
• Play as one of two bipedal robots
• One is made of a personality core, the other is made from a turret
• Each player will have a portal gun (yes, four portals at once) with either player able to use the other's portal when needed
• Either split-screen or online play with a picture in picture option to see what your partner is doing
• Co-op maps will be more difficult than the single player maps due to the nature of communication and bouncing of ideas off of partners

***** SPOILER ALERT *****

Kotaku has found some infro from GateStop regarding portal:

Coming this holiday. Portal 2 is the sequel to 2007's Game of the Year and draws from the award-winning formula of innovative game play, story, and music that earned the original over 70 industry accolades. Features single and multiplayer co-op modes. The single-player portion of Portal 2 introduces a cast of dynamic new characters, a host of fresh puzzle elements, and a much larger set of devious test chambers. Players will explore never-before-seen areas of the Aperture Science Labs and be reunited with GLaDOS, the occasionally murderous computer companion who guided them through the original game. The game's two-player cooperative mode features its own entirely separate campaign with a unique story, test chambers, and two new player characters. This new mode forces players to reconsider everything they thought they knew about portals. Success will require them to not just act cooperatively, but to think cooperatively.

This more than confirms our belief that Portal 2 will have coop.

Kotaku has also found more information on Portal 2's Bad guy.

Cave Johnson, the boss of Aperture who was dead in Portal, will be the principle antagonist of this sequel. How? We'll get to that.

In the game, Johnson, described as an amiable self-made billionaire who refuses to accept the responsibility of his power, starts off as a sort of sidekick to the player but then he starts to lose his grip on humanity as the story progresses. According to an open casting call we received in 2008, at some point in the game, after Johnson has isolated himself from the people around him and lost touch with reality, he becomes the main bad guy.

There is a "megathread" over at facepunch about Portal. "Max of SD2" has assembeled all the information about Portal/Portal 2 obtained so far form the SSTV embeded in the audio, the BBS ASCII art, as well as some other interesting tidbits.

View more by clicking here

Sequel to 2007's Game of the Year Coming This Holiday March 5, 2010 - Valve, creators of best-selling game franchises (such as Left 4 Dead, Counter-Strike, and Half-Life) and leading technologies (such as Steam, Source), today announced Portal 2 for shipment this coming holiday season. Portal was originally released in 2007 and earned over 70 industry achievement awards. For more information, please visit www.steamgames.com

* WARNING THE FOLLOWING CONTAINS SPOILERS**

Hectic Glenn over at halflife2.net has made an interesting connection between the new/modified ending and from the scene where you escape the fire pit. Take a look at the youtube video below:

Updates to Portal have been released. The updates will be applied automatically when your Steam client is restarted.

Portal

•  Added valuable asset retrieval

Zips over at CSNation has a rather lengthy and in-depth report on the latest Portal update including images from the SSTV (Slow scan TV) feed and ASCII art from the BBS system that was found.

Valve is either hinting towards some new release/update or is just messing with us. Either way this has been a fun update. Have you found all 26 radios yet?

Updates to Portal have been released. The updates will be applied automatically when your Steam client is restarted.

Portal

• Changed radio transmission frequency to comply with federal and state spectrum management regulations