My warrior has 5 level 80 epics in the bank. They are in the bank because my warrior is only level 77. The moment he hits 80, he'll be wearing a good number of purple gear. And that isn't just me having too much gold, it is an environment in which you can get kicked out of a pickup group for not wearing epics. A commenter recently said on this blog that "purple is the new green". Not quite, but there are sufficient arguments to make the point that purple is the new blue.
The "color inflation" has two reasons. One is the fact that raids are easier. But the other is that crafting is now much better. There are complete sets of great tanking and damage blue armor (level 76 to 78) from smithing, which are extremely cheap. I assume the same is true for letherworking and tailoring. And all these professions can make affordable bind-on-equip epics, for around 1,000 gold a piece if you count the cost of materials and have friendly crafters in your guild. And that is just what you can get before even hitting level 80, afterwards you can get more epics easily enough by doing PvP if you are solo, or by running heroics if you can find groups.
On the other end of the scale that means that green items are now vendor / disenchant trash. I haven't worn a single green item through all of Wrath of the Lich King leveling with either priest or warrior. A blue item that is better is always within easy reach, and at level 80 you quickly acquire epics. The main disadvantage of that color inflation is that quest items are still green for any quest that isn't a group / dungeon quest or the end of a long quest chain. Thus gearing yourself up by doing quests has become a rather rare occurence.
With everyone wearing epics, of course they don't feel "epic" any more. I'm sure that in the harder raid dungeons to be patched into WotLK in the future, there will be more legendary items, orange becoming the new purple. Makes you wonder at what color the loot in the next expansion will arrive.