Heh. Indeed.
Of course, seeing as how folks can self-select their level of challenge, via notoriety and self-imposed limitations (EX: no sets, no temp powers, nothing from START vendor, and so on), I feel like this is pretty much covered. I do wish there were more work done on the low end of the spectrum. By that I mean the 10-30 experience.* But that, too, is addressed in a lot of player-created content (that few people play). Fact is, the options are there. The Devs are focusing on where the majority of the population seems to be, which is the higher level content. This is great if your standard approach is to join the uber-build arms race (which seems to be almost mandatory, if you want any sort of satisfactory play at higher levels). That said, there's just tons of content available for those who want a slower approach. As for challenge, this, too, is mostly in the hands of the players.
*though, to be fair, we DO have new content in the 20-30 range, EX's Watkins and the new Striga contacts.