It looks like the new Mtn Dew General Store for 2014 is ran through Facebook and not on its own website like previous years. The link www.thedewgeneralstore.com will redirect you to the Dollar General Facebook app.
UPDATE: The link thedewgeneralstore.com/en-us/Enter goes to a version of the site not hosted in Facebook.
Basically it’s still the same promotion 1) Buy any participating Mountain Dew® products at Dollar General® Stores beginning 2/26/14 through 12/21/14 to earn points. Buy Doritos® with your Mountain Dew® and earn (1) bonus point 2) Set up your Dew® General Store account and enter code(s) from your receipt(s) to earn Dew® points in your account. All codes must be entered by 12/21/14. 3) Redeem your Dew® points by 12/31/14 for great Dew® Gear. (Free shipping included!).