Schmoe wrote on Jan 19
th, 2012 at 12:31pm:
So your solution is that instead of allowing characters to advance their level, you would allow them to advance in level but call it something different. And then you would put in some sort of arbitrary correlation between quest "level" and the new "not-levels". Of course you haven't said anything about rating gear for the new "not-levels", so maybe you also planned on some sort of arbitrary correlation there, unless you didn't, in which case you're back in the same boat of having no quantifiable way of correlating character power to content challenge.
I guess I just don't see the elegance.
Arguing about how they could have done it is somewhat moot, because it won't change a thing.
But to adress your question:
No correlation between quest level and "not-level".
Doing Epic quests will grant you Epic XP. There are Epic Ranks, but no levels beyond 20. If you are capped and you do an Epic quest, you get epic xp, where the amount is regardless of the actual epic rank you have. So a lvl 20.1 char has access to the same content as a lvl 24.9 (if you wanted to translate it back to actual levels).
There is no power-leveling penalty for running a lvl 20 character with a lvl 25 one, and there are no access restrictions to enter Epic Quests besides having level 20.
Any level 20 character (with Epic ranks or not) will not inflict a power leveling penalty, or nullify bravery and streak bonuses, or inflict an xp penalty for quests which are of the appropriate level now for getting these bonuses with a lvl 20 character in it.
The ML cap is 20. There are no items with a higher ML than 20.
This way, the introduction of epic levels will be an option to pursue when you are capped, but it won't feel as required as it would be the case if the number which appears in LFMs is not the maximal number ('bah, that toon is not done yet'), or if there were items which are inaccessible due to ML: 25.
I see that a level cap increase seems to be elegant at first glance, but I don't like the feeling of this too much, because of the issues I addressed above.