I've thought often about the inherent "arms race" and mathematical complications arising from the increased bonuses in leveling.
As PC's To Hit increases, so does Monster AC.
As PC's HPs increase, so do Monsters'.
As PC damage increases, so does Monsters'.
These increases are balanced, right? So why don't they just cancel each other out?
It seems to me that somewhere in the formulae all this is a wash, esp. in a system as tightly balanced as 4E. I wonder if a 3rd level combat lasts X rounds, for instance, but so does a 14th level combat last about the same number of rounds?
I think an approach like Sadrik's recognizes that increase on the PC side is matched by an increase on the monster side (and vice versa), and could simplify things a great deal without changing much at all.
PCs and Monsters would still get cool new abilities, feats, etc., but the math would seem to remain a static element.
The wrinkle would be, as posted earlier, low level PCs fighting high level monsters. If you just called the per level To Hit increase a wash against the per level increase AC, HPs might even that out.
(As an aside, I've also toyed with the idea of having something like 1st level PCs just march out into the world, without their per level increases in To Hit, Damage, and AC, but keep the Monsters as is. Hey, some monsters are just, well, monsters! But, need to kill Radamanthus, the Ancient Red Dragon but you still have your 1st level To Hit, Damage, and AC? Maybe you need to search the FarKeep Ruins for the fabled Sword of Galador the Dragon Slayer...?)