Good article. While I use my Boxster year round, I also have a separate set of winter tires, so both sets will likely get older before they get worn from mileage. Will have to do some research on the compound in the winter tires, but next season I'm due for new rubber all around. (Note to self: get more track time and wear them out before they dry out!)
A quick article on how to read the DOT date code:
How to Find Out How Old Your Tires Are
Another on tire aging via Edmunds:
How Old - and Dangerous - Are Your Tires?