I don't think that making the early levels harder to
attain is going to help new people feel like they belong at
all. I still remember being a new user and enjoying watching
my XP grow. Spread those levels out and you're going to
make it worse for new people (IMO).
I would also be in favour of some kind of "downsizing" of
the current levels, but only if we can think of a good way
of doing that that will seem fair to the people who are
downgraded. Can you suggest a suitable scheme? (that's
not intended to be snide or condescending, please don't
read it that way.)