Had this problem last night used several methods, looks like the stain is gone now. White vinegar seemed to do pretty well by itself. Blotting the spill with paper towels or clean cloth is the first step. I then poured white vinegar all over the stain, and blotted it up with a clean towel.

This worked for the majority of the cleaning, but I could still see some pink tint to the carpet.

I then made a mixture of 1 teaspoon dish soap and 1 cup hydrogen peroxide. Using a sponge on the stain with this mixture took care of the rest. Followed up with rinsing the area with warm water on a sponge, and blotting dry.

I found this last tip here on the web:

http://www.ehow.com/how_2526_remove-red-wine.html