I generally think power rankings are pretty meaningless, but Jonah Keri does a good job of summarizing every team's weekly activity. It's virtually impossible to keep up with all 30 teams, so I find Jonah's recaps a good resource.
The interesting thing here, aside from the links and factual tidbits, is where the teams on the Pirates upcoming schedule are ranked according to Keri. The Pirates open their homestand tomorrow with three against the Twins (No. 28) and follow with three against the Tigers (No. 20). They then go on the road for four against the Phillies (No. 22). They play the Cards (No. 12) in St. Louis for three, but then come home and get the Astros (No. 30) for four.
While the Pirates have lots of issues and the peripherals suggest they are unlikely to maintain their current winning percentage, they do get 14 of their next 17 against teams in the bottom third of the rankings, at least according to one analyst.
Oh, and Keri has the Bucs at No. 16, right between the Blue Jays and the Marlins.