...UPDATE: For Mac users, I'm saying that ABBYY Finereader for Mac (8.03) is not worth even downloading the trial. They don't have a deskewing feature at all, it takes forever to process 50 pages, etc.
This leaves us with a few dedicated pro-level OCR/Scanning software apps for the OS X platform: Readiris, Omnipage Pro X, and Adobe's Acrobat. (My last attempt with Omni was brief because of instability.) It seems that all the OCR products are all focused on being primo for PCs and lagging for Macs.
However, some relatively good news for Mac only users: Readiris 12 Pro/Corporate for OS X is in fact straightening my images; my theory is that it's probably an essential step to crop the raw images BEFORE processing in Readiris. (The alignment software is likely getting confused as to where the page starts and ends.) It appears that it bases its alignment feature from the vertical text-lines to the image border, but I've seen images get partially straightened from what looks like 2+ pages appearing in a captured image. If I was a readiris bot, I'd be confused too...
