Wikipedia allows users to leave feedback on each article. Experienced Wikipedians analyze this feedback in myriad different ways to improve the Wikipedia user experience and to improve the encyclopedia itself.
The Wikimedia Foundation has been creating a new Article Feedback system, and on Saturday 9 June from 10AM-noon Pacific time, WMF invites testers and anyone else interested to participate in a "shakedown cruise" to test a near-final version of the new Article Feedback system before the system is rolled out to all of Wikipedia.
Following on May's successful test event with Weekend Testing Americas, WMF is teaming up with the Open Source fans at OpenHatch.org for this event. I am hoping that having experienced exploratory testers plus people interested in improving Wikipedia articles will be a killer combination of expertise and interest to shake out any final issues in this critical aspect of the Wikipedia experience.
Note: anyone who shows up on 9 June will have access to some of the Article Feedback features, but if you create an account on Wikipedia no later than 4 June and also make at least ten edits to Wikipedia, your account will be "autoconfirmed" and you will have access to many more Article Feedback features than a casual user would. (Feel free to edit for instance the Wikipedia article on your home town, or an article on software testing, or dice games, or if you're shy, just update your User page and your Talk page a few times, those edits count toward the ten also.)
This is the announcement and there is an optional sign up sheet. The Article Feedback Test Plan has all the details