About fedoras evolution?

[Mats]

Hi, 
I have tried to find information about fedoras evolution but haven't
find an answer to the following question:
How long will fedora 12 be supported with security updates?
I'm coming from ubuntu and used to the idea with LTS-versions (long time
support) but I like some of the security philospohy in fedora more.
Will fedora 12 be a more mature and stable version in the long run to
use? More tested and so on? I know that I have to do some of this
judgement by my own.

/Mats