Ok - how about this for another resolution sub-system? Skill check is roll 1d6 per skill rank +1 die, plus Attribute Bonus, sixes explode. Add results, roll total over 9 for success, all ones is a botch. The total of the roll is Quality of Success - AKA Base damage - in combat add Weapon Damage Bonus. Constitution is 2X Physical Attributes - average human Constitution is (7.5 X 4) X 2 = 60. Attributes are capped at 15. Edges and Traits add 1 to the roll for each point used. Optional - Mooks go down with 35 points of damage in a hit, die with 60, and anything less is a wound. Mooks fall over with three wounds. Initiative is roll 1d6, highest goes first, players can trade points to roll and vice versa.
I put this sub-system together in my head as I walked home from work. It was raining lightly, so I couldn't read as I normally do while walking. I began breaking it down into ranges of expected results, which gave me the Constitution multiplier and the TN. The TN is 9 because the unskilled person without high attributes needs an exploding six, plus at least an average roll on the bonus die, to make it. At Skill rank +1, it's still difficult, but not nearly as hard as for the unskilled person.
I really like that skill is much more important than attributes - it's one thing I never liked about skill+stat+roll systems. I also like the skill gradient - a master can be devastatingly good, while a tyro is only dangerous if he gets lucky. This would be one bloody system in combat. This could very well make it into StarCluster 3E.
Thanks to Narf the Mouse over on The RPG Site for the suggestion! He asked about a roll-and-add d6 system with exploding sixes, and this popped into my head.