life cycle of fedora4

[ody quraviharto]

hello all, 
firstly I'm a newbie of Fedora. I wonder to know why Fedora release
version so soon?
I've just installed FC2 a year ago and now FC4 is released.
I'm afraid that my FC2 can't be upgraded and goes into legacy product. 
As a Linux user, I'm concerned installing new version of Fedora
instead of developing application on Fedora, yes so my job is
installing the new version, installing on and on.
do I have to move to another longer-life-cycle distro?
Thx