Last modified: 2014-03-17 14:23:09 UTC
"currentevents" is specific to Wikipedia (but even the Hebrew Wikipedia doesn't use it, and it's especially odd in Wikinews) and "sitesupport" is specific to Wikimedia. Both of them are not generic like "portal" or "mainpage". I suggest to remove their messages from Messages.php, and from the messages "sidebar" and "monobook.js".
"Sitesupport" is not specific to Wikimedia, there are a lot of wikis out there that would need donations &c. in order to keep them running. "Current events" could be altered to be specific for events on that site. This stuff is simple to remove from the sidebar and it does no harm; I see no reason to remove it.
*** This bug has been marked as a duplicate of bug 14710 ***
This is really a duplicate of bug 2424.