Our company is evaluating the enterprise edition of Forms and Workflow, which would be deployed to a SP 2010 premise based platform. Can workflow solutions be exported to the BPMN 2.0 XML format?
Nope. It'd be nice, huh? It only exports to .nwf file. Only imports .nwf files, as well.
Depending on the complexity of your workflow, however, reconstructing it manually probably isn't that big of a deal. The hardest part is always just getting the process designed accurately and thoroughly in the first place.