The linked page is currently down, however you can see release notes here:
<a href="http://www.mozilla.com/en-US/firefox/4.0b9/releasenotes/" rel="nofollow">http://www.mozilla.com/en-US/firefox/4.0b9/releasenotes/</a><p>Or, there's a style-less Google cache of the actual blog post:
<a href="http://webcache.googleusercontent.com/search?sclient=psy&hl=en&client=firefox-a&hs=5VJ&rls=org.mozilla%3Aen-US%3Aofficial&source=hp&q=cache%3Ahttp%3A%2F%2Fblog.mozilla.com%2Fblog%2F2011%2F01%2F14%2Fthe-next-major-version-of-firefox-is-ready-to-test%2F&btnG=Search&aq=&aqi=&aql=&oq=&pbx=1" rel="nofollow">http://webcache.googleusercontent.com/search?sclient=psy&...</a>