Both TIFF and PNG are loss-less. TIFF uses the LZW compression (and others) that some may still remember from the days of command line computing. PNG was intended to replace GIF. There is also JPEG-NS (near loss-less) and JPEG2000 (loss-less), which are much better suited for photographic images compression. Adobe has their own loss-less format too, Digital Negative something (to save RAW images).
Yup, but RAW files are generally 2-8 times those of JPEG. As per the article, the file size will not be much larger.
JPEG images are generally not the best quality. They're fine for everyday use, but not if you're looking at large prints.
There's always going to be a trade off between file size and quality, IMO.
Depends on how large you want to print I guess - nobody is saying this is going to be a technology that completely replaces everything that has gone before. I think (as does the company) that the large file size is a complete non-issue.
It is quite logical too - for large images to be printed the file size is no issue... and for web/screen applications the compression will be just as acceptable as the widespread use of JPG is today.
Interesting interview with the CEO of Lytro:
While he acknowledges the the use of the Lytro technology in other areas, he stops short of confirming that it will be licensed. Also, he confirms that you need the Lytro software in order to interact with the image.