I'm going to go ahead and thought experiment this from two perspectives:
Scenario 1 -- characters are assaulted in a large, natural cavern by a horde of goblins.
Scenario 2 -- an ancient dragon, disturbed by some burglar, attacks a lakeside town.
In Scenario 1, we can expect lots of move around and through goblins and heroes, lots of swinging of swords and other implements of death, and general mayhem associated with combat. Since we are talking about a D&D adventuring party, we can expect spells to be flung, backs to be stabbed and innards to be spilled.
Therefore, we need to know the following about the goblins in this scenario: their ability to slice and dice PCs (to-hit probabilities and damage), their ability to avoid getting sliced and diced (their physical defenses, plus their hit points), their ability to avoid getting sleeped or charmed (their mental defenses) and their ability to avoid getting otherwise impeded (saving throws of various sorts). We need to know how fast and perhaps how well they move. We need to know if they have senses that are better or worse than average (dark vision, perception). We need to know if they have any weaknesses or particular strengths or bonuses. In case certain circumstances come up, we need to know what their general capabilities are (climbing, figuring out who may be lying, etc...)
As such, I would suggest a reasonable stat block for goblins might include: AC, Initiative, Movement Rate, Attack Bonus, Damage, Saves, Physical Bonus/Penalty, Mental Bonus/Penalty, Special Bonus (for super skilled goblin flanking, frex). Taking a look, we can see there's still some redundancy. In 3E especially, the save categories reveal all sorts of information about the creature. Moreover, to-hit bonuses tend to imply a degree of prowess as well. So perhaps we can fold these together and go to Action (attack), Fortitude, Reflex and Mind (Will, Intelligence, etc...) bonuses. Swinging a sword and climbing a wall are the same Action roll, while shrugging off poison and swimming across rough waters would both be Fortitude rolls. Armor Class -- or defense -- would then be Reflex plus Armor Bonus, giving us an easy calculation for flat-footed versus touch ACs. Reflex could cover initiative, Mind could cover perception. So now we need only Movement, Armor, Weapon, Action, Fortitude, Reflex, Mind, Special Qualities (dark vision), plus that special goblin flanking maneuver.
Moving onto Scenario 2, does the previously mentioned stat block still work for a dragon? Kind of, it seems. We need all that information, but we also need to know how fast it flies, and how well (another Move value, and then what? Action or Reflex covers Fly checks should they be necessary?). The dragon likely has a large number of special abilities, possibly including spells and/or spell like abilities. However, if we standardize these, then perhaps we can keep the stat block small(ish) even for an elder wyrm.
Now, this approach certainly sacrifices a "grainer" level of detail. Where are feats and skills? Do we need them? Can we fold these into our bonuses and our special abilities, respectively? If we are playing Pathfinder, where does CMB and CMD fit in?
Obviously, it isn't a complete "system" -- just a thought. Bemchmarks would have to be made and specifics regarding skills and other "stats" would have to be decided. But I think there's something there, a potential shrinking and easing of the stat block that makes "winging it" and general game prep so much easier.
