In Adobe Acrobat 9, I was able to export multiple PDFs to a PDF/A-1b format. However, I cannot find that functionality within Acrobat X.
Thanks for the suggestion. Unfortunatley, that only works to export/create one PDF/A at a time. I am looking for a way to create multiple PDF/A's at a time. (in Acrobat 9, it used to be under File > Export > Export Multiple Files...)
The closest I have seen, is using the Tools > Action Wizard to create an action that 1) asks the user to pick the files, 2) runs Preflight (with some PDF/A-1b preset settings), and 3) asks the user to select the save location. However, when I run this, it does not always create a compliant PDF/A on all the documents (where running the Save As option individually does create a compliant PDF/A document).
I know it's been a while, but might this be what you're looking for?