The first Lytro light field camera is already in production according to this article from AllThingsD:
"Meanwhile, many on Lytro’s team have been shuttling between Silicon Valley and the Asian manufacturing facility where the first cameras are being produced. While the design itself has been fully baked for some weeks now, the company has been working on smaller refinements and on validating the manufacturing and supply chain process."
The first Lytro camera is expected to be released by the end of the year (you can see a blurry shot of it here).
See all Lytro related stories here.