I always said that the Left 4 Dead 2 whiners would come crawling back once the game was actually released, and Valve used kindness to prove it. Two of the most vocal boycotters were flown out to Seattle on Valve's time and invited to give the game a chance. They are now eating crow and have to admit that the game is a worthy sequel.
"Things seemed balanced and 'tight' and did not feel like a rushed job. While we were visiting their offices we personally witnessed what can only be called a small army of artists, coders, mappers hard at work, which explains the rapid transformations in artwork that we've all seen," grovel the turncoat boycotters, known by the impressive handles of Walking_Target and Agent of Chaos.
"What we can say with confidence is that the quality of gameplay in Left 4 Dead 2 is not in question; and it will only get better."
Naturally, the other boycotters are angry (read: jealous) and now accuse the two former comrades of selling out. They have had to defend themselves from those who believe they are wearing the moneyhat: "No, we didn't pay for flights or hotels, and we are fully aware of how that looks. however, anybody who has had to spend more than 2 hours in an airplane can tell you it's no treat. Nor is getting the sh*ts from different water and food in another part of the country, that's always fun."
So, the boycott is not over, but Valve has shown that until these people actually play the game, their protests are meaningless. Most of these protestors will go back on their word by the time this game launches.