I think that it already does support, if not require, that mindset. It's just a question of how easy it is for the PCs to see that.
Thinking purely of combat:
Everyone in the party goes on the same Initiative count.
Increase the overall party benefit of attack spells. For example, a Fireball now does 1d6/2 levels, but it also leaves anyone damaged by it flat-footed until their next turn. Every rogue now loves the party wizard.
Flanking is more forgiving and more powerful -- it works for anyone in the normal flanking position, plus one square to either side, and it provides +4 to hit, not +2.
Fighters get more use from ordinary combat feats, and it all benefits everyone in the party. If a Fighter has Combat Expertise, his shouted combat orders give everyone in his party a +1 Insight bonus to AC -- this goes to +3 if the Fighter uses a move action to shout specifics. Same deal with Power Attack and damage.
Rangers give everyone in the party 1/2 their favored enemy bonuses.
Anyone with Evasion gives the rest of the party a +2 Insight bonus to Reflex saves. Anyone with a save-boosting feat does the same thing (Iron Will helps you AND the rest of your party).
Each time a rogue gains another d6 of Sneak Attack damage, he picks a new ability that goes with that Sneak Attack damage. The abilities benefit the party -- for example, losing 2d6 damage but causing a monster to lose its first attack per round, or losing 3d6 but causing the monster to take a -4 penalty on all saves, or even losing 5d6 but causing the monster to lose an entire turn.
Most buff spells work on the entire party now, not one person.
All detection or interaction rolls now use one roll. For example, only one Spot check for the entire party, using the best available Spotter's bonus, with an automatic +2 for each additional person in the party with at least 5 ranks (and an additional +4 for each additional person in te party with at least 10 ranks).
Wizards and clerics lose some of their big damage spells but gain unlimited medium-damage abilities (like the warlock's eldritch blast) as well as the class ability to make a limited number of magical items that can be distributed to the party. In an ordinary D&D game, this is most of the magic the party gets -- monster magical items are cursed and evil and must be destroyed, although a wizard can observe the magic and learn to copy it. This removes the big looting issue, and also removes the XP penalty for magic-item creation that aggravates wizards.
All these abilities dramatically increase the party's power, and so the flip side is that the DM alternates between increasing the power of the opposition or having the opposition use similar tactical powers. This makes it a bit like World of Warcraft, where realistically, you can't solo past a certain point -- the game is designed assuming that it's you and your friends working together well, because if you aren't, they paste you all over the floor.
This is all off the top of my head, and I'm sure a lot of it would be horribly broken in play. This is just to get the ball rolling.