According to this Sports Illustrated Article, Tony LaRussa is planning on continuing his trend of batting pitchers in the 8th hole, and putting a "second leadoff" hitter in the 9th spot.
I can see some of the reasoning behind it, and the Cardinals are kind of an exception because their pitchers led the NL in OPS in 2007.
But, inversely, the strategy can backfire. Each spot down in the batting order receives about 20 less Plate Appearances over 162 games. And what about when there are ducks on the pond for the 8th place hitter? In most cases, I'd rather have Aaron Miles in that spot instead of your average pitcher.
Using one of my favorite toys, Baseball Musings Lineup Analysis, I'll do a couple quick and dirty experiments just to see what effect some different lineups have. I'm using the Baseball Prospectus PECOTA projections.
Just to keep things simple, I'll give it a shot with both Miles and Brendan Ryan in the 9th hole, and flip back to "traditional" to see how it changes expected Runs Scored/Game. I'll do it using the team average stats for pitchers in 2007, and also using Kip Wells, who is a batting stud.
Basically, with the average Cardinals pitcher, the best situation is either Ryan or Miles batting 9th and the pitcher batting 8th. In fact, this combination results in about an additional .130 runs/game. This may not sound like much, but over the course of a 162 games, this could result in 20+ additional runs. With Kip Wells pitching, the advantages go even higher for batting a position player 9th.
So maybe Tony LaRussa does have something here. But even with this radical lineup change, he is missing a big opportunity. According to Lineup Analysis, the best lineup possible is one which features Pujols batting 1st and the pitcher batting 6th or 7th. By doing this, it adds over an additional .1 run/game. I think it's safe to say that we will never see such a crazy lineup in a modern MLB game though.