Wine is at its best when it's in the right temperature range
Most foods show best when they are served within certain temperature ranges. Wines are the same way. Served too cold, their aromas and flavors will be muted, and the phenolics and acidity emphasized. Served too warm and the alcohol will evaporate too rapidly, making the wine seem blowsy and alcoholic.
For the full article, check out the new issue of Wine Spectator, on newsstands October 31, 2005.