What is the shelf life of red wine?

Really depends on exactly what it is.
Some wines are designed for drinking early, while others benefit from careful cellering.

It depends on the type of wine it is and more importantly the details of the storage of the wine. If it have been kept in a dry. Cool environment with little disturbances then it should age well. Heavier red wines with higher tannins tend to do better. There are not many red wines that benefit from aging.

Aging of wine - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Aging_of_wine)
How Long to Age Wine (http://www.cellarnotes.net/howlongtohold.htm)