It does look encouraging, because it was such a long (too long in my opinion) wait between v4.8 and v4.9; I almost thought that they had stopped development on the Reader.
I think what "hardware resistant PID" means is a PID based on the hash code of the Pocket PC (similar to Microsoft's
activation scheme), so that even if you hard-reset your PPC, you won't have to key in your new PID and re-download the DRMed ebook.