I love the idea of using "Unreleased G2 repaint ideas" as a theme for a whole subline. It got me thinking of other possible ideas for themed groups of figures to release, and wanted to see what other people thought of as well.
The "rules," I guess, would be that it would have to be a group of figures from recent lines (or otherwise known available molds, like the G1 reissue stuff they're doing now) repainted and/or slightly remolded, similar to what we normally get in these sort of lines. Otherwise, the sky is the limit!
Here's one from me:
Renegade Rampage: Move over, Decepticons, there are some new villains to contend with as the evil Go-Bot Renegades find themselves thrust into the Transformers Universe!
Cy-Kill - Remold of Wreck-Gar/Junkheap with a new head
Cop-Tur - Repaint of Siege Spinister
Fitor - Repaint of Thrust