Digital Editions 1.5 has support for DRMed ePub, even though no real books are available yet. I assume that's probably what will be used in Sony's implementation.
Code:
<label key="migrateLogAdeEbxEpubOk">ADE EBX ePUB imported:</label>
<label key="migrateLogAdeEbxEpubBad">ADE EBX ePUB failed to import:</label>
<label key="migrateLogEbxEpubConvOk">EBX ePub converted to new License:</label>
<label key="migrateLogEbxEpubConvBad">EBX ePub failed to convert to new License:</label>