In the AL my heart says A's, my head says Yankees.
AL playoff predictions:
A's or Angels over BoSox
NYY over Twins or ChiSox
Then NYY over A's/Angels
It's going to be frustrating for the Red Sox fans. I think they take the Yanks in a seven game series if they face them, but will lose to the AL West champ in the divisional series.
The NL is a complete toss-up, which is a lot of fun. Other than Montreal, Pittsburgh, Colorado and probably Arizona, every team is currently within striking distance of leading their division.
If everyone can stay healthy, then the top 3 NL teams (IMO) are Cubs, Marlins and Astros. Really, it's going to be a dogfight in all three divisions right up until the end. It'll be great, as will the playoffs - which will come down to matchups.
WS prediction: Yankees over Cubs. Hell stays hot. Pigs still don't fly.
Hopeful prediction: A's over Giants. Beltran hits the series clinching home run, followed by a 1-2-3 9th by Graves/Urbina/Blanton ... Rhodes (?)

"The game has a cleanness. If you do a good job, the numbers say so. You don't have to ask anyone or play politics. You don't have to wait for the reviews." - Sandy Koufax