I propose that an additional checksum of the revision text be added to the mediawiki database and that this checksum be made available via the database dumps and api calls.
This additional field would allow many computations such as revert and noop detection without having to ask the system to provide the full text of revisions. For example, if I were to build a user script to show users which revisions have been reverted, it would be beneficial to not have to ask the API for the full text of a large list of revisions. On that same note, even when I need the full text of revisions, I could determine which revisions I do not need to request by determining that their content is exactly the same as one that has already been retrieved.
It does not seem that such a field would require considerably more storage or computational power since computing an MD5 checksum in PHP is cheap and storing 32 hex characters compared to the size of an articles text is not appreciable.
Thanks, -Aaron Halfaker