Zac,
Thanks for letting us know! Are you trying to access that URL in a browser, or inside the Install Software flow from the Eclipse Help menu? To my knowledge, you can’t directly access the update site in a browser.
Alternatively, you can open the Eclipse Marketplace inside Eclipse from the Help menu, and search for Webclipse.
We’ll double check things on our side, but the site does look up and responding fine. One of the files you can directly access is:
http://www.genuitec.com/updates/webclipse/ci/p2.index
Cheers,
Tim