I've just started playing it. Seem like it has no where near the mood and atmosphere of the original (thanks to the absence of GLaDOS and the addition those annoying English/American synthetic voices that everyone seems to love these days), but it still looks very good.
Well, in more Portal news, there have been some cryptic Easter Egg-like updates to the original game. the update log reveals some interesting stuff.
A new achievement has been added, called Transmission Received. Now, if you pick up the radios scattered around and hold them in certain places, you'll hear Morse code. The code translates into what appears to be some sort if boot up sequence.
There are also other bits of code, like SSTV coded images, and a phone number for an old BBS service.
There's also a new ending. If you remember, Chelle escaped, ending up in the Enrichment Centre's carpark where it faded to black. Now, however, Chelle hears a robotic voice say "thank-you for assuming the party escort submission position," then gets dragged away.
There's other stuff, too. An awful lot of Easter Eggs for the nerd.
So, what does it all mean? Opinion is split between Portal 2's imminent release and Episode 3's release. Personally, I don't mind which one. Just looking forward to the most immersive and captivating game series I ever played.
Head over to the Steam forums for in-depth info.