Yes, high-level PC's are easily the equivalent of low to mid-level superheroes, and can be run as such. In fact, I recently ran a session of my campaign where the party ran afoul of the "Sembia Six", a stalwart band of crusaders for justice. Read on...
The party had been hired by an unknown patron to sabotage some research at the local Thayan enclave in Sembia. Seems they were working on some powerful enchantment item that would allow a corrupt nobleman to influence his fellow councilman very easily. So the party goes in, and one of them (an ex-patriot drow rogue with mad skills in demolition) blows up the research tower where the item is being made. The party flees, but not before being seen. So, the Thayans decide to have Sembia do their work for them, and send their own men (disguised as the party) out to destroy a small town. Now, the party has the Sembian government out to get them.
Fast forward a bit, and the party has just re-entered Sembia (they were in the Dalelands). They hear about the warrant out for their arrests, and have to sneak back into Selgaunt (a port city). Pity the poor minotaur who has to hide amongst a herd of cattle. One of the party manages to steal a district tax map, and notices an abandoned town on it that has no tax notations. Figuring it to be abandoned, the party heads there. Little do they know that this is the secret headquarters of...The Sembia Six!
These stalwart heroes are:
"The Defender", a Ranger 1/Paladin 6/Devoted Defender 6/Exotic Weapon Master 3, specializing in the use of twin dwarven axe-bucklers.[Superhero archetype - Captain America]
"Deadeye", a Fighter 8/Rogue 4/Peerless Archer 3, specializing in embarrassing the enemy with called shots [Archetype - Hawkeye/Green Arrow]
"Blackrock", a Fighter 1/Monk 5/Stonelord 9, using the power of the earth to slow and hinder the enemy [Archetype - kinda like Geoforce, without flight]
Shenar, a Sorceror 6/Elemental Savant 6/Frost Mage 3, all cold magic, all the time [Archetype - Iceman/Killer Frost]
Cassandra, a Monk (Invisible Eye school 3/Psion (Seer) 12, using her powers to forecast the battle and outwit her foes [Archetype - Moondragon, without the bitchiness]
and finally
Graaahhh!!!, a Gray Render Barbarian 6. 'Nuff said.
The party gets ambushed by these guys and manages to hold their own for a few rounds, until Deadeye goes down to a lucky spell, and Graaahhh!!! goes into a rage because somebody hurt his "little buddy". He knocked the minotaur back 20 feet into a house (demolishing it, of course) for almost 60 points of damage, and was about to paste the rest of the team when the seventh member arrived...
Chaney (after Lon Chaney, man of 1000 faces), a Doppleganger Rogue 2/Monk 6/Spymaster 1, their info gatherer and secret weapon [Archetype - Mystique]
He changed into Deadeye's form and managed to calm Graaahhh!!! down enough to explain that he knew about the frame-up, and that the two groups should really team up and take on the Thayans together. The party couldn't, of course, but it was classic super-hero fight based on mistaken identity, and it worked really well.
