Prereleases are September 27 and 28, and Launch Parties are October 3, 4, and 5, and this special mythic rare alternate-art promo is stamped with the date the set goes on sale. You could get two if you played in both events!
Neat, huh? And check this out: it's going to come in six languages! To see it in all its non-English glory, click on your favorite language (Klingon not available):