Twitter changed its logo. What do you think about it? http://blog.twitter.com/2012/06/taking-flight-twitterbird.html
There's not much of a difference, but I would go with the new one because it's "cleaner" and more simplified.
I would keep the old one. Seems more neutral, this one is a little like a church bird or something lol.. The other one accommodates nicely to other things..
It's only a bit different, but I like the new one than the old one. It looks more powerful and professional and just like someone said the old one looks childish.
This new one is easier to recreate, maybe if they want children to draw it, it is more useful. And the color pops more than the original.