The drag and drop support is like working with any YUI drag drop object. What you implement with that is for you to decide.
Drag and drop sorting of rows is a good example of using drag and drop. I've been thinking about what examples I will do with this release and that's a good one.
I'm glad you like the paging interface. I don't think scrollbar based loading is going to make it into this build. I've implemented it partially but there are just too many things to override to support sparse row population. I will have to create a new GridView for "virtual" mode. I don't think I will have time to do that in this release. It was slated for the next release anyway, but I really wanted to get it into this one.
It's paired with reordering columns and both are high priority for the following release.
Most of the time on this release was spent on editing, the new flexible loading/paging code built into the XML and JSON data models and the redesigned layout/rendering code.
The 3rd one (layout redesign) was needed for reordering and fixed columns and should make them both easier to implement.