A couple of data points from the commercial side of the house:
We use i2S' software for this called Book Restorer. http://www.i2s-bookscanner.com/produits ... 1_EDI_1003
It is a proprietary and rather expensive piece of software which we bought solely for two reasons: this algorithm (which is generally referred to as Geometric Curve Correction) and its Lighting Correction algorithm, which essentially evens out hotspotting, gutter shadows, and other illumination flaws on scanned pages. Both algorithms do an excellent job. The rest of the Book Restorer suite, IMHO opinion, isn't that great, and Photoshop does all of the same stuff, but better. But we thought it was worth the price just to have access to these two algorithms. We have used the Curve Correction with great success on actual book scans shot with our CopiBook as well as with tens of thousands of page images digitized from microfilm using non-i2S equipment. One drawback is that the text blocks, once straightened, sometimes become slightly trapezoidal in shape, but our customers feel that's much better than having to deal with the curve sloping into the gutter and poor OCR accuracy.
Note that this is a software-only solution, with no special hardware required. You tell it what page / text components to key off of and the software does the rest. The biggest problem with the software is that it's single-threaded -- processing only one page at a time -- so a single roll of microfilm yielding a few thousand grayscale TIFFs will take hours to process. But we just let it run all night / weekend on a batch, and stuff gets done faster than you'd think.
Out of respect for our dealer, I can't comment on Book Restorer pricing, but it's more expensive than something like Photoshop etc.
Zeutschel has a similar product, but I believe it's only compatible with their scanners -- best to check with them or one of their dealers. i2S' software is great because we can run any old image files from any scanner / camera through it and it does its thing.
Hope this is of interest . . .