So, after seeing the preview pics of Kup and Scourge and realizing both molds are quite familiar, I started to think....
Firstly, I get the impression from many peoples' posts (not from just here) that it is assumed that FunPub can choose virtually any mold in Hasbro's legal arsenal, with the exception of molds co-owned by other entities (Paramount Pictures). I've heard it mentioned (although not from an authoritive source) that they also don't have access to molds currently on shelves. From a completely subjective perspective, I can't believe FunPub would have such vast choices and still chose the mold for Kup that they did. So, here's what I think....
Hasbro supplies FunPub with a list of available molds (source: Pete @ Botcon). This list IS NOT LARGE (my theory). I'm guessing 20-40 molds. I'm also going so far as to suspect that these molds have no dust on them, either because they were just recently used or are expected to be used soon.
Basis:
2009 Boxset (Wings of Honor)
Kup - recently used for Movie repaint Crankcase
Scourge - recently used for Universe repaint Ratbat
2008 Boxset (Shattered Glass)
Optimus Prime - relatively recent Classics mold
Grimlock - relatively recent Classics mold
Jazz - recently used for Movie repaint Jolt
Goldbug - recently used for Movie repaint Breakaway
Starscream - recently used for Universe repaint Dirge
2008 Extras
Ricochet - recently used for Movie repaint Jolt
Rodimus - relatively recent Classics mold
Sideswipe
Blurr
Megatron
2007 Boxset (Games of Deception)
Thundercracker, Dirge, Thrust, Bugbite and Dreadwind - relatively recent Classics molds
2007 Extras
Mirage - relatively recent Classics mold
Weirdwolf - relatively recent Cybertron mold
Alpha Trion - relatively recent Cybertron mold AND recently used for Universe Vector Prime
Huffer - relatively recent Cybertron mold AND recently used for Movie Armorhide
Springer - relatively recent Cybertron mold AND recently used for Universe Roadbuster
I'm not familiar with previous years.
So, the only three that don't perfectly fit in with my theory are 2008 Sideswipe, Blurr & Megatron. Perhaps all that means is that we can expect to see Hasbro use these as the basis of repaints soon?