I suppose there will be no problem with the laptop and the eReader. "Just" deauthorize and authorize them and they will now show the new email address. But, what happens to the already purchased books that are DRM protected? And what is an AdobeID anyway?
If it is just an email address once that one changes then no previous DRM protected material can be read. If that is the case how does Adobe and those content providers relying on an AdobeID handle cases where the customer changes or has to change his email address ?