TPU came across rumors that October 15, 2013 is the day that AMD will left the NDA over the Radeon R9 290X graphics cards. This means reviews will start hitting the web that day, but doesn't necessarily mean that the card will be available on retail stores. On top of that, there's also a rumor that AMD will not permit its partners to release non-reference versions of the R9 290X in the short term, the only exception being models fitted with full-coverage waterblocks.
This NDA expiry time was disclosed in the slides that AMD showed the press. There's always the possibility that the NDA expiry date doesn't match market availability. It could merely mark NDA expiry for the press to post reviews of their AMD reference-design R9 290X (the only kind of R9 290X that will be initially available).