We have been tracking the Google Caffeine index for a really long time. We recently reported it was almost live but today is that day - Caffeine is live!
What took so long? Well, we knew it would launch soon but due to mormons being upset with the code-name "Caffeine," due to their dietary restrictions, Google had to change the name.
Changing names is a very political and long-process at Google. Google, being Google, decided to go with the German spelling, "kaffein." A German chemist, Friedrich Ferdinand Runge, came up with this in 1819. So due to the issues with naming it "Caffeine," Google decided to put the breaks on that and use a less known word for it, kaffein.
Now that Google Kaffein has been renamed, Google has now taken it live.
Webmasters at WebmasterWorld seem to confirm the launch of kaffein. We have dozens of reports that it is now live, the reports starting coming in last night.
This does not appear to be an April Fools joke!
Forum discussion at WebmasterWorld.

Comments:
haseeb najam
04/02/2010 11:02 am
Well thats the lamest april fool joke for any seo ....especially for the ones who believe it :P
Martin Greenwood
04/06/2010 12:55 pm
great news - I assume it's live cos I'm getting a new search results page? http://www.specialisedseo.com/google-update-search-page/
Jim Adams
04/21/2010 05:25 pm
Nice post. The link to webmasterworld was very helpful. Looks like a lot of shaking up on the Google front.