Well this is interesting, and if you're not a journal aggregator, good news. According to Peter Suber, Google is offering to digitize and provide OA to the back runs of scholarly journals! Peter's got all the details on his site, but I'll jump right to one of his comments towards the bottom that says, "I don't see a downside for journal that doesn't already have a digitized back run. Google will charge nothing to do the job, the contract is non-exclusive, and it needn't include current issues. The only journals that might hesitate are those already selling online access to their back runs and happy with the revenue."
Off to forward this information to several professors on campus who are involved with journals...
(originally found via Michael Geist's blog)
Update: Dorothea Salo's not very pleased with what's known about this project. You can read her post here, and Peter's followup here (Dorothea doesn't allow comments on her blog) (nor does Peter, for that matter).