There was a playtest some folks did at the wizards site with a tarrasque and a party of 5 or 6 (forgot) andthey took it out in 2 rounds i think it was and the tarrasque couldn't attack back...I believe they did max the characters, but the fact that it's even possible in a standard system shoudl have been taken into account...since from what I see, most campaigns are focused on combat; and thus, everyone maxes their characters anyways...
Orcus.prob not..but the same concept stands...epic stuff really isn't very epic.
Stoat - i detailed some stuff that we do to make combat a lot more dynamic..using orcs, a dragon, and a marilith as an example...
I can send you that for example. it's not by the book, cause personally, by the book 4E doesn't work for my group (in terms of, they hate it and want to go back to 3 or even 2E in comparison)...
Sanjay