RE: Drag and Drop

Given that the first possible use would be for a smaller group of

internal users 

do you think that the browser and javascript requirements might be

manageable?  

Any place that might quantify the support needs?

Yes, for internal apps it's extremely manageable. The "support" needs
(as in ongoing support) aren't the issue, it's whether the browser being
used supports the DOM and javascript required. Basically, if it's IE6+
or Firefox or Safari, etc. you're typically ok, it's when you have a
public site and want to support those people still using IE 4 or 5 and
Netscape 4.7x that you've got big problems. 

On the development side though there are differences between IE and FF,
so make sure you test for both. Most good frameworks (as in javascript
helper routines, not huge things like Struts or Atlas) will abstract
away the browsers differences so you don't need to worry about them.

-Walden