New Supreme Court justices appointed every 2 years?

I've been hearing discussions about revamping the Supreme Court, specifically the way justices are appointed and how long they serve. Unless the Constitution is changed, they have to serve for life. A new theory is to have the President elect a new justice with each new Congress (every 2 years for those of you who flunked Social Studies) and the most recently elected 9 would be the Surpeme Court of the land. What would you do with those elected who are not part of those 9? They'd be doled out to federal courts where needed b/c the Constitution doesn't say they need to serve on the Supreme Court for life, just that they get lifetime terms as judges.

I think this is an interesting theory, I like it. Or, they could have mandatory retirement ages. Or have 20 year terms. Or whatever. The discussion today on NPR was that when the founding fathers gave away lifetime terms, the life expectancy was only 39 so the idea of a person serving for 30+ years was practically unfathomable (Alicia - did I use that word correctly? I think I did...). So adjusting the system makes sense since the way it is now encourages "convenient" retirements when the party in power is your friend.

Here's an article that talks about what the justices think of changes in the Court (read it, it's funny not dry).