Was is the planned longevity of Yii? Will this framework still be around in 1, 2, 3 years? I know that no one can tell what will happen in the future however the reason I am asking this question is that the the person who started this framework also started another framework a while back, Prado (which I know is still around). I don’t want to standardize on a framework that in a year the leader developer goes off and start another one.
have a good time with yiiframework!
PRADO was released about five years ago after winning the ZEND PHP5 coding contest and is still maintained. However, PRADO users were encouraged to try the new Yii framework since it combines some of the best ideas from PRADO with the MVC architecture.
As a long time Open Source user (and even contributor sometimes 
) i can say: If you need clear answers to those questions, OS software might not be right for you. Everything is volunteers work and you can’t expect any guarantees. I’ve seen a lot of projects die, because people’s interests and lifes change and you can’t force anybody to continue working on something that doesn’t matter for him/her anymore. We have to accept that.
If, on the other hand, you have some average PHP knowledge and you’re not afraid to “get your hands dirty” and look into the internals of a framework, i see no problem with the above fact. If there should be problems in 3 years and noone cares about Yii anymore, so what? I’ll always be able to help myself, because the framework code is still there. I might not come up with the perfect code then, but i’m definitely sure i’ll be able to fix problems. That’s all that matters for me.