Think of it this way: how long did it spend where it was before it got put in the can? ummm.... 200 million years or something....
As long as it doesn't have condensation or rust in it, it lasts a very long time. I think you're in good shape. I would recommend though, that in the future you store it with the old oil in it, and change it when you start using it again; that way if it dies get condensation or any other contaminants in it while it sits up, you get rid of them.
------------------
"So many Mustangs, so little time..."
ICON Motorsports