On April 29, I listed several players that might be due for offensive turnarounds based on their high line-drive percentages and low BABIPs. Here is a then-and-now comparison.
Travis Snider (aka The Amazing Sniderman) was a turnaround player prior to landing on the DL. On April 28 he was batting .125-2-4 in 75 PAs. His OPS was .503. Since then, he batted .385-4-11 in 55 PAs. His OPS was 1.187.
A.J. Pierzynski was batting .167-0-3 in 66 PAs. His OPS was .431. Since then, he's batted .254-2-10 in 75 PAs. His OPS was .716. His OPS the past three years was .732, so he's approached his norm.
Nick Johnson gets an incomplete after landing on the DL, although his OPS went from .617 to .963 in the six games he played prior to getting hurt after April 28.
Jhonny Peralta was .190-1-6 in 79 PAs. His OPS was .631. Since, he's .272-2-12 in 88 PAs. His OPS was .799 (.756 average the last three years).
Jeff Clement saw his playing time cut and also saw his OPS drop in limited action since April 28.
Finally, Luke Scott was .213-2-7 in 68 PAs. His OPS was .688. Since then, he's gone .324-7-13 in 77 PAs. His OPS was 1.039.
So, overall, improvement was evident.
As a related aside, I noted on May 4 that Austin Jackson's numbers were ridiculous. In 63 PAs since, he's batted .259 with a .628 OPS.