I spent a little time breaking down the odds for the ALDS and thought I'd share.  I'll post the links to the ref. materials after a brief explanation and then I'll dump the results.  

As the backbone of the system I chose BP's ELO rankings.  I think it's a great system, captures margin of victory and all that good stuff.  Plus it does a much better job of capturing things like injury trends and the big MO than the raw, component stat rankings do.  Basically, it has more predictive value than any other system I've seen out there so I'm using it as the baseline.

For the rankings you can check out BP here:
http://www.baseballprospectus.com/statistics/ps_oddselo.php
For some info on ELO and the math behind single-game probs you can go here:
http://en.wikipedia.org/wiki/Elo_rating_system
Finally, for a look at the way those single-game probs translate into series probs you can go here:
http://www.diamond-mind.com/articles/playoff2002.htm

And now the results:

BP ELO rankings of AL playoff squads:

1570  Twins
1569  Yankees
1556  A's
1546  Tigers

Likely playoff breakdowns:

73%:
NYY hosts MIN
DET hosts OAK

27%:
NYY hosts DET
MIN  hosts OAK

ELO-based % chance that the A's will win a given game against a
possible first-round opponent (independant of starter, home field
etc.):
DET:  51.4
MIN:  48.0

resultant probablility of a series victory based on the single-game
prob, using a +4.2% modifier for the hometeam:

DET:  52.9%
MIN:  46.6%

-in other words, the playoffs are a crapshoot... and go Tigers.