This whole offer reeeks of shady.
The Admin at EA.com's forums keep deleting posts about the offer. The end date of the offer has changed 3 times on EA's official website. The offer supposedly ends tomorrow, and no one at EA has spoken up to answer everyone's questions.
Readers at Joystiq, Kotaku, Cheapassgamer.com and other sites are not happy. Personally, I'm struggling with what to buy (if anything).
I bought Battlefield 1943 at the discounted New Years price, but I've seen some people say that doesn't count towards the offer since it was a discount. EA is missing out on at least 2 additional purchases from me unless they cough up some answers in the next 12 hours.