To expand upon what jinguy posted:
One year: 2000 / 365 = 5 reputation
per day. That means every other day
you would have to earn one upvote. If
you aren't doing that, then you aren't
a 'contributor' (at least one that I
would trust editing my posts).
I would argue that this reputation number should be higher to the tune of 3,000 or so in a calendar year. The ability to edit posts should be for current active contributors and someone who is not maintaining 3,000 points in a calendar year is probably not a very active contributor.
Maybe new proposal:
Increase reputation threshold to edit posts to 3,000 points within the last 12 calendar months (last full year from today).
I just made the official proposal here:
Increase reputation limit to gain "EDIT" privleges