When is bloons tower defence 5 coming out

On the 3rd of January 2011.

Since it is already November of 2011, you can already tell the other post was completely inaccurate. It was scheduled for May 6, 2011, but due to technical difficulties, it was moved to October 2011. Now they are saying late 2011, meaning probably sometime during December. Sorry if this isn't accurate enough for you.