The official name for Android 4.4 - KitKat - was made official a while ago, but back then we got no release date or feature details. Last year Google announced the Android 4.2 and Nexus 4 on October 29, so many people are expecting an official Google event around the same date this year.
KitKat has recently posted a yet another teaser for the next release of the Google platform that seems to be hinting at October 28 as release date.
The first tweet came yesterday, saying "Everybody dance now!", which refers to a C+C Music Factory song, a group previously known as 28th Street Crew (until 1989). This was indeed a vague clue, but today's hint is a bit clearer - "This is it".
As you've probably guessed by now, "This is it" refers to the popular Michael Jackson movie that premiered on October 28, 2009.
It appears then that Android 4.4 KitKat is coming on October 28, and it will probably be joined on stage by the Nexus 5. We already know pretty much everything there is to know about the next Google phone, but here is hoping Google will still find a way to surprise us.