Since most of the folks here registered within the first week of FTM's existence, the distinction between "newbie" and "veteran" is a bit specious.
If your point is that as time goes by, that distinction will become more relevant, then registration dates, which are shown for all users, should be a way for newcomers to distinguish between newbies and veterans.
If you're worried that some folks will have been around for a long time without providing much troubleshooting help, well, they're likely to continue not to do so, so guarding against their unproven advice by publicizing their low post count is unlikely to be an issue.
The point is to guard against the assumption that newbies are inclined to make that those with the highest post counts know the most—an assumption which is very difficult to temper when those with the highest post counts are statistically the most likely to reply to any post!
