I actually didn't see it, but someone said...
... they basically changed her fate from escaping to being recaptured. If that is true, that is pretty stupid. It is like they didn't want to spend the time and resources designing something with a portal gun in a new more open setting, and instead tried to find a way to put her back in the facility to have an easier time designing portal 2.
No, nothing that drastic at all. from my understanding, it just showed that GladOS is still alive...which isn't a surprise at all considering the entire ending song
Actually...
The original ending had GlaDOS blow up, and you end up outside on the ground where flaming debris falls from the sky. The facility blew up or something, but you escaped. It fades to black.
All of that happens still, but before the fade to black we hear a robotic voice (not GlaDOS, something else) that says something like "Thank you for assuming the party escort submission position" and then you are dragged backwards one step at a time. Then it fades to black.
So yeah, its only a few added seconds but it does sort of change the feeling from "escape" to "recaptured".
Here's what I like about the change/addition:
It suddenly adds interest to an older game and a possible sequel. Maybe it'll sell some more copies or get people playing again, just to get people check out some of the new stuff - especially since it's FREE. It's good to keep older game alive by updating, adding content, etc etc.
Here's what I dislike:
Since this is a linear game w/ no real decision-making or anything and all (unlike say a deep Bioware RPG might allow) - it basically changes the game's one ending entirely.
So, instead of escaping, now you're being captured.
So, now it feels like I'm suddenly transported into another parallel universe, as if the original ending I received meant pretty much not as much as it should. There there isn't any options. No option in which I can select at the start of the game the option to receive "Original Ending" or "New Ending." There isn't someway in-game, in which my how well I'm playing or bad playing, I can earn either ending - whether it's b/c in how many hours I finish the game, not dying at all earns me a certain ending; or whatever. There is no special difficulty setting to end a different ending (like Max Payne 2 does - giving you a much happier ending if you beat the game on its hardest difficulty).
So, now I'm stuck w/ the new ending period - especially since Steam forces updates on you for you to actually keep playing. Obviously, the "New Ending" is the set-up for the direction of a possible sequel.
Kudos for Valve trying something different to keep interest in an older game and for a possible sequel - but "bleh" on them for the poor execution of this attempt.
To be fair, in the original ending, it just ended...this adds a couple of seconds. I get what people are saying about escaping or being captured, but this isn't the same thing as a retcon. A retcon would be if you never got out of the facility - that's all the first game showed. There was no final shot of your tombstone with "She lived free from captivity for the last 50 years of her life" on it.