Better than the Internet.
I know this is a terrible thing to say, but I'm not that interested in Portal II. The first one seemed the perfect example of an awesome stand-alone game and I see no reason why there should be a sequel unless they've got a ton of new, great ideas to keep me interested.
Interesting. I would buy another Portal game just for new levels and puzzles, even if none of the technology had changed. I loved the first game, but felt it was short and wanted it to be longer. The fact that this sequel has a bunch of new interesting game mechanics makes me desire it all the more.