Relax. It's okay for people to get to level 4 quickly
when they actually post decent stuff, because that sort
of positive reinforcement encourages decency (very effectively, I think).
The jump from 5 to 6 (from XP200 to XP500) would, on average,
take at least as long as the whole progression from newbie
to level 5, and so it's not surprising to see a clump of
folks who hit a "plateau" there.
As for the gradual but inevitable growth of the saint caste,
if PM were a for-profit corporation and our saints were
managers and chief officers, this sort of growth
would be bad. But since PM is an all-volunteer, all-pro-bono,
altruistic mob, having more people at the highest level just
makes things better for everybody at all levels (even for those
levels less populated than the saint class) -- it means more experts to
share the SOPW load, more diversity of expertise, better jokes
in the CB, you name it.
If/when I reach that level, it'll be meaningful for me, no
matter how many others are there by that time, no matter
how many more come in afterwards.
update:
Having thought a bit more (and looking at some other replies), I wanted
to stress this one point about XP and levels:
it should not be about climbing into ever more rarified and exclusive
upper ranks. It's about accumulating a common wealth of
experience, such that people are accountable (get credit)
for the experience they contribute. A lot of
effort is invested to make sure the wealth can be
shared as openly and effectively as possible. When there are more
saints, the whole community is richer, and I don't see a
problem with that.