This is one of the big improvements in CRM 2011.
REUSABLE JSCRIPT LIBRARIES!!
Richard Knudson who has a great blog and I am always getting great articles and videos from his site. He has an article and 12 minute video explaining web resources
http://www.dynamicscrmtrickbag.com/2010/11/12/extreme-2010-recap-taking-advantage-of-web-resources/
This is a great improvement for CRM 2011 because now we will be able to use the same javascript in multiple forms without having to duplicate it everywhere.
Another thing I noticed from the video is how much easier and faster it is to get customising the forms.
It is quite different from the previous way of working but I don’t think that is really a bad thing.
Richard also wrote another blog entry on Re-usable JScript Libraries
both of these blog entries give you a great introduction to these new features in CRM 2011