FYI, for jQuery those links appear to be interesting (bout jQuery 1.3.3 news, and performance tips) :
Also some guidelines for jQuery selector performance (they need to be tempered with the previous articles which are more up-to-date) : http://www.artzstudio.com/2009/04/jquery-performance-rules/
Do we need base OOP library also?
I think no
We have baseComponent class as base class for our components. We can extend this class in feature if needed