Having a random Wikipedia entry served to you as your homepage is one way to expand your knowledge, but the lack of any quality filter means you could be served up any old thing. Fortunately, there's a way to get random featured articles delivered to you, but instead of only having it as your homepage, why not configure it so any new tab or window fires up a dose of potential worldliness?
To have a random featured article served to you, you'll need to hit up this URL:
The steps required to automate the process depend on the browser you're using. Chrome users, you can download the extension "New Tab Redirect" to painlessly configure the browser's new tab behaviour. For Firefox and IE users, here are your instructions, courtesy of "WK_of_Angmar" on Reddit:
Open a new tab, go to about:config?filter=newtab.url, click "I'll be careful" and change the newtab.url preference to what you want.
Internet Explorer 9 users:
Go to Internet Options -> General -> Settings (under the Tab heading) -> Change the "When a new tab is opened..." setting to your first homepage.
Depending on how prone to procrastination you are, or the potential annoyance of having Wikipedia load in any new tab, this might not be the most sensible tweak to apply. However, if you like a little bit of added knowledge in your day, with the benefit of knowing what you see has had some sort of quality filter applied, you could do worse than this tip.