It could be a US regulatory thing. There are still no EPA fuel economy numbers for it, nor any NHTSA or IIHS data. I'm not sure the "rules" for selling vehicles without at least some safety and efficiency data available, but that would be my two cents.
(Further speculation) Not to mention getting more of a marketing push, probably mass market (non-enthusiast) "announcement" with a super bowl ad, coupled with a launch ad during the NCAA basketball playoffs.