Gold Ursaring (who knows a thing or two about events) from The FAQs speculates that it might be similar to the Deoxys event that was held in Japan. The only DS related Deoxys event so far (according to serebii.net) is:Serebii says there are rumors of special moves and a special item. I hope to god this is true.
Level: 50
OT: 10th
ID No.: 07147
Ball: Cherish
Item: Nevermelt Ice
Ribbon: Classic
Then again, it doesn't take a genius to say that it'll probably come in a Cherish Ball with a Classic Ribbon and most likely level 50. Interestingly enough, the moves that Gold Ursaring listed for the Japanese Deoxys event did not contain any special moves.