From Inbox to inbox

I know its a wrong time to post on the blog, given that I have 2 end term tests today. But a small thing that I noted yesterday morning is running through my mind for a long time. If you have checked your Gmail Inbox carefully, the label is now inbox (with a small 'i'). And they have changed it everywhere today, starting from label, to page title, to all references in the interface, and even the references in the description of the Labs settings. (though they couldn't change pictorial references :) ). Scoured the blogs to find no official/unofficial explanation to it. Do you see it as an April Fool's hoax released a day earlier, so that people start talking about it? If it was something so carefully changed, Google has always broken the news on its official blogs, including changes in its favicon colours. Do let me know if you are aware of the reason.
Update: It seems the change isn't visible on all accounts. Some of my friends still see the capital I. I have tried changing location, theme, switching over to the old version of email, but found a small i welcoming me everywhere :(. Finally, I checked the Gmail gadget on my iGoogle page, and it still shows a capital I (inspite of similar settings)

Update 2: This April Fool's Day is a big letdown from Google. It has posted an obviously hoax feature called CADIE (Cognitive Autoheuristic Distributed-Intelligence Entity), an Artificial Intelligence research and blah blah, with images of a Panda cartoon shown its mascot. As if the name wasn't a giveaway by itself, the press release is date 31/3/09 11:59:59pm,it generally doesn't 'time' its releases, though it gives the date), its technical description uses too many scientific/psychology/physics/computer/jargonology jargons, the official post (dated 1/4/09 12:01am) doesn't mention clearly what the 'CADIE' does, and its CADIE's blog is designed like a 5th grader's 'My first Web page - Hello World!'. They couldn't even use the Youtube channel effectively. Google had been improving on its hoaxes in the past, with atleast some amount of beleivable stuff and simple English (with typical Google terms). I am disappointed that this year's prank is not at all planned and seems to have been executed by a 5th grader! I still wish the "inbox" change is a prank so that they can live up to their fans' expectations :)

Update 3: Finally, Andrew Girdwood came to the rescue! The small i is visible only if the language settings are English(UK). I changed it to English(US) and voila!, I see my Inbox intact! And people thought I was playing an April Fool's prank on them :)