Write a question about the following article: Detroit advanced to the NBA Conference Finals for the sixth straight season, squaring off against the Celtics. This put the Pistons second on the all-time list of most consecutive conference finals appearances, only behind the Los Angeles Lakers who appeared in eight straight conference finals from the 1981-82 to 1988-89 seasons. They lost Game 1 88-79, but won in Game 2 on the road, 103-97, marking the Celtics first home court loss in the  postseason. Immediately following that, the Celtics won their first road game of the postseason, 94-80, in Game 3. Game 4 saw the Pistons win 94-75. In the pivotal Game 5, they lost 106-102, despite rallying from 17 points down late in the game. In Game 6, the Pistons entered the fourth quarter leading 70-60, but a lack of focus, a poor game from Rasheed Wallace, and a rally-killing turnover by Tayshaun Prince ultimately led to their demise; the Pistons ended their season with an 89-81 loss. After that, the Celtics went on to win the 2008 NBA Finals. On June 3, 2008, the Pistons announced that Flip Saunders would not return as head coach.

Question about the article:
Which team did not win the 2008 NBA Finals, Celtics or Pistons?