The second 'L' is actually a '1', and in this case .... so is the first.
It didn't take a lot of investigative work to figure this one out.
Mouse over the logo and it says "Google's 11th Birthday". (Tapping the logo brings a search of Google .. ugh ... on Google ... which doesn't reflect anything about a birthday).
Google has been low key about this one. Maybe we'll see something on the Official Google Blog this week. On the last Google Birthday, (the big ten), I wrote this piece over on Louis Gray's blog.
In reality, according to the incorporation papers, Google was founded on September 4th, 1998.
Will it become a news story? Probably. Almost every 'special' Google logo over the past ten years has made the news.
So, to the whole crew at Google (around the world) .... and the few Googlers I've come to know (mostly electronically) over the past few years... Happy 11th Birthday Google!