1. AL East (Average Team Rank: 12.2; Average 2010 Wins: 86)
2. NL East (Average Team Rank: 13.8; Average 2010 Wins: 83)
3. NL West (Average Team Rank: 14; Average 2010 Wins: 82)
4. AL Central (Average Team Rank: 17; Average 2010 Wins: 80)
5. NL Central (Average Team Rank: 18; Average 2010 Wins: 77)
6. AL West (Average Team Rank: 18.25; Average 2010 Wins: 78)
Eyeballing this, it appears about right both in the general sense and its proximity to the divisions' performance in 2010, which makes me feel better about the rankings. The AL West is the worst division in baseball; three out of four teams had a record of .500 or below, it included the second worst team in baseball, and despite this pathetic competition the division champion Rangers had the worst record of all playoff teams. The NL Central has been the worst division until last year, so proximity to the bottom makes a lot of sense as well; some key acquisitions by the Brewers and a strong 2010 performance by the Reds helps the fact that four of six teams finished below .500 last year and the division champion Reds tied for the worst record of NL playoff teams and second worst record overall despite playing the Pirates, Astros, Cubs, and Brewers a bazillion times. The Central was the worst division in 2010, as clearly shown, but the Brewers' moves, along with my beliefs about the Pirates and Mariners, dig them out of the cellar for me. For those who thought that the Pirates deserved to be the worst team in the majors, swapping them with the M's led to a Central ranking of 18.33 and a West ranking of 17.75, so you may still think that the Central is the worst division. In any case, it's quite close, and the two are almost certainly the worst divisions in baseball; I suppose if you had issues with my placement of the Mariners, A's, and Angels the West might overtake the Central, but then you run into issues when looking at 2010 performance.
The AL East is of course leading the pack with three teams in the top 10, and payrolls account for that. Some also thought my ranking of the Rays was too high, which is certainly possible, and that the Yankees were too low. These largely offset each other, though, so they likely don't have much relevance to the divisional rankings. The NL East really isn't far behind its AL counterpart, again understandable as Cliff Lee has been added to the division, Jayson Werth didn't leave it, the Marlins and Braves are brimming with young talent, and the Phillies are the best team in the NL. The NL West is very close behind, though, and this is exactly in line with my thinking; the NL West features four theoretical playoff contenders, and the worst team in the division is the Diamondbacks, who really aren't that bad. Sure, their pitching is God-awful, but they can hit. If the Nats hadn't signed Werth or didn't have a few interesting arms and nice prospects the D'backs would be the best of the worst. Arguments can certainly be made for the NL West as the second-best division in baseball; it doesn't have a powerhouse like Philadelphia, but there are four good teams who will all be looking to try and make the postseason in 2011.
The AL Central in the middle is bolstered by the Twins and the Tigers' and White Sox' additions of Martinez and Dunn, coupled with the fact that all three teams were good in 2010 and should be better in 2011 (except perhaps the Twins). The Royals and Indians really drag this division down, though that won't be true of Kansas City in a couple years.
There is also a sizable gap between the NL West and the AL Central; three places and the .500 mark separate them. This is also where I would distinguish between good divisions and bad divisions; the AL Central does have potential, but I'd like to see how bad the Royals are and how well the Tigers' and White Sox' new additions play before I give them that label.
All in all, I think this turned out fairly well. There was some debate on a few rankings, but by and large I'd say this is a fairly accurate list, a notion reinforced by what I feel are accurate divisional rankings produced from the previous posts.