Courtesy of TFW2005.com, a UK Wholesale listing obtained via FullMetalHero.com all but confirms what was an expected assortment.
Here is what was contained in the Hasbro UK listing:

1) Prime Deluxe Assortment
2) Prime Voyager Assortment
3) Prime Entertainment Pack
4) Prime Role Play Blaster
No details on who will comprise the line or a release date yet, but Botcon and the SDCC are not too far away.