Well, I look forward to it. You have a great community here to seed a reddit clone.

I would advocate adding the ability to ignore users who join after a specified date. This would allow everyone to freeze the community just the way they like it. I think it would be an elegent hack in lieu of competent recommendation.

I think the trick to preserve the "old reddit" on a new site would be to allow people to choose whose stuff they get to see, i.e. filter by users. That way the early elite doesn't have to get washed out.

It'd be easier to just let the site get too big, sell it to a major company, and then start over. You can't lose!