For those unfamiliar the new data will be at 500 meter resolution (the previous Blue Marble was 1 kilometer resolution). There will be 12 versions - one for each month. You'll now be able to see seasonal changes.
Also, the oversaturated (in the histogram sense of the word) desert areas in the old Blue Marble have been improved. Plus new processing was done to better handle temporal and reflectance variations (i.e. clouds artifacts). More information is here:
http://www.iac.ethz.ch/staff/stockli/bmng/
In reference to the sheer amount of data - and quoting from 'Jaws' - "You're going to need a bigger boat."

Lone