In one of the stackoverflow podcasts, Jeff pondered the idea of having a reputation limit. The concern was that certain users (e.g. Jon Skeet) will get so far ahead and might discourage other users. I don't particularly see that as a huge problem because most people aren't doing this in order to become the #1 user on the site. On the other hand, promoting competition for good questions and answers is certainly a goal of the site, and being an early user of the site leads to a higher reputation and doesn't evenly promote the competitive spirit.
One way to address this would be to have two stats next to everyone's name: their total reputation and their "average reputation" (total reputation divided by the number of days that they've been using the site). Alternatively, you could put a "rolling reputation" (the reputation over the past year, for instance). In essence, you could base it on a sports metaphor: this a new reputation season.
What do people think? Would that be worthwhile? Of course, I would still expect the top users to lead in this category (over 200 a day), but it would also motivate late adopters.