http://googlecode.blogspot.com/2009/11/introducing-closure-tools.html

All of these new libraries would be wonderful to use, but do you think
it would work in conjunction with JQuery or require all the javascript
to be rewritten? If that's the case, do you think the features they
offer in the library are worth the learning curve and redesigns?

I'm just curious as to your thoughts in general on this and whether or
not it is worth learning to use. I'm just starting to design a fairly
large application and at the point where it might be worth it to
incorporate this new stuff since I'm early in the design stages.

I've read some of the docs, I'm just curious to hear anyone's opinion
on features they are excited about or not.