Wikipedia Watchlist checks your watchlist and updates the badge on the browser action icon to reflect new changes. Clicking on the badge opens up a popup where you can highlight different changes to view their edit summaries. Clicking the little 'd' will take you to the last difference for the page and clicking the page name will take you to the page itself.
Comments are greatly appreciated. Please let me know what you think.
v18.104.22.168 2014-05-25 – Fixed bug where all article links are diffs.
v22.214.171.124 2013-12-28 – Fixed bug in localization of watchlist link.
v126.96.36.199 2013-10-04 – Added option to automatically mark changes as read after closing the popup.
v188.8.131.52 2013-10-04 – Fixed logged out bug. Added customizable update delay to the options page.
v184.108.40.206 2010-08-22 – Added options page with the ability to choose which language Wikipedia to watch.
v220.127.116.11 2010-08-17 – Fix pruning of old unreads. Made timestamp always visible.