Portal was one of the greatest games ever made and it was only 4-5 hours long. I can't see how anyone could think the sequel being more than twice that length is a bad thing.

I also wouldn't assume it will be $60. At least not unless you're planning on buying it for a console, but even then it depends on who's publishing it. As for a PC release though, we're talking about Valve here. The company that pretty much gives more value for what you pay than any company making games right now.