I'm not particulary fond of the new system for Space Marines non-vanilla chapter, but that's not the point : basing on the fact just one mini gives varation on the SM armies, do you think GW will plan to release new special characters ?

From a commercial point of view, this could have a lot of advantages : just one mini to product that is based on a allready existing army (potential new player, and some old players mad enough to buy SM again to go along ^^), the additional profile can easely fit with the codex by just an additional page on the GM website/on the WD...

The remaining question would be then : what kind of new special rule can be added ? "Give universal rule X" or "Y can now take objectives" are really boring, could it be something else ?