I've heard some of the threads on early levels (I hit performance elsewhere) - here is my personal take on this:
a) The tutorials work well (we've focus tested the heck out of them) for folks new to MMOs, but if you've played an MMO, they are too slow paced. b) The more skilled of the player you are, the more you want things to go "off the rails" and have more abilties/etc. in combat sooner - and more difficulty. You often hear quoted "the game kicks in at level 15" (or 20).
So our answers: Just recently we added in more powerful monsters across all levels/areas. This means that a kill quest gets more interesting - kill one huge creature, or slews of easy ones? It's your choice. We're looking to let folks opt out of the arkship levels. Not sure when that will hit, but it'll help for those who are like "yeah yeah I know".
We also look at the data for when folks drop out - believe it or not (I know everyone feels like their experience is that of everyone) there isn't a HUGE amount of data support; we have really high retention levels through 10, 15, and 20. But there are some hot spots where drop rates go up (and we work on fixing those places).
Another thing we can do better: communicate all the ways you can play. If you don't like the 6-20 experience, PVP is a great option (but we don't really highlight this in the UI) Etc. etc. Some lowbie dungeons might help the hardcore too (but aren't really in the hopper per se unless we move some items around - feedback welcome).