A few recent changes, hope it was in time for MediaWiki 1.11 release:
* list=logevents updated - more event type decoding, leprop= allows to specify exactly what data is needed. log_id is now exposed. Some result might be different than before. This list needs some feedback and attention.
* userCanRead() has been removed everywhere - now API will work for the users that have read permissions for the entire wiki (see $wgGroupPermissions variable settings at http://www.mediawiki.org/wiki/Manual:$wgGroupPermissions ). userCanRead() will still be called when requesting page content.
* API no longer checks for the maximum upper limit restrictions when calling api internally
* rc_id is exposed in list=recentchanges requests
--Yuri