I think people are making a lot of fuss over nothing. Yes, it may end up being slightly over-priced (I felt the same about the first one, so waited until Christmas), but that it strictly speaking has more content than the first says more about the first than this new product.
Having listened to the Rock, Paper, Shotgun podcast with the interview, I do believe the effort is sincere, if perhaps a touch misguided. I personally believe the biggest problem with the whole situation is the addition of "2" to the title. Were there merely a subtitle, it would be perceived as an expansion/standalone addition off to the side instead of the high and mighty moniker of sequel. If the Director 2.0 had been called the Director 1.5, people still wouldn't complain, even if it held all the same features. That strikes me as a failure of marketing, not concept.
The good thing with Steam is, as has been shown, they can experiment with price structures and throw in perks up the wazoo. I imagine they'll be largely necessary to paper off this PR blunder, along with at least one more content update (I'd guess a campaign). If people really purchased L4D with the intent of investing in future updates, especially considering all the update pricing shenanigans which have been present since day one, they are more than a little bit naive.
Honestly, my only complaints are that it might mean another cold winter for TF2 updates, and no informed progress on EP3/whatever-orange-box-spectacular-they-might-have-planned. That's a shame, as there's more heritage in those franchises which scream Valve, though the lack of success on 360 would suggest a reason.
Hell, think about it for a second: this recession has made Valve attempt to make a game in a year. Is crazy.