"... Do we/can we collect search queries on en:wp?..."
"...It would be ridiculously easy..."
http://vps.epstone.net/~andrew/wiki/index.php/MediaWiki:Common.js
"...yes...no privacy implication... How many searches do we get a day? Is this useful data to those working on MediaWiki/Wikipedia search?..."
I think all users, especially editors and those who want to add new pages could benefit from such a feature. I suggest insuring that the word(s) searched for show up in red if there's still no page. In other words, more than just what was searched for, but if it was found or findable via that search (and maybe if it was selected or discarded).
Any other ideas on features and benefits? Sounds like an opportunity to create SpecialSearchStats.php for all MediaWiki installs.
Perhaps even coordinating it with SpecialStatistics.php?
Someone did a nice job with http://en.wikipedia.org/wiki/Wikipedia:Search_engine_statistics but that's navel gazing - where "Wikipedia" appears in Google. What's more important to me is what people are searching for on other search engines, with an eye to help identify where Wikipedia is unresponsive to people's interests. For Google, see the weekly list at http://www.google.com/press/zeitgeist.html and the hourly feed at http://www.google.com/trends/hottrends ... versus whatever we think should be on Wikipedia.
... I know we're busy with v1.12 testing, and that basic function comes before such enhancements as above ... funny thing, though, when there's loads of money behind something: standing at the gas/petrol pump credit card terminal early this morning as they turned it on and it booted up (everything's computerized) I saw it's BIOS was v20.2!