I've been making streamgraphs of the offensive production of every MLB team for the 2012 season.
Here is the Pirates Streamgraph
I probably can't tell you anything you didn't already know about last season, but the takeaways are that the offense lost a lot of momentum after the all-star break, and while they got big contributions from players like Neil Walker, Pedro Alvarez, and Garrett Jones, that those contributions came in bunches, and not in a consistent manner across the whole season (Walker is obviously exempt for any inconsistency in the 2nd half).
While this chart has little predictive value, it will be interesting to see if the Pirates can build on their first half successes of last season with an injection of young (and old) talent, and perhaps some more consistency from their bats not named Andrew McCutchen.
If you like (or hate) the chart, I'd love to hear your feedback.
An explanation of the details is under the "What is all this" link above the chart.