Hi,

For WebDropDown , LoadOnDemand is basically identical to the WebDataGrid's Virtual Scrolling, which is CTP.

Lazy loading is a general concept that can be interpreted in two ways i guess:

1) load on demand and paging

2) in WebDropDown - not having initially loaded items at all, and on some event - such as opening the DropDown, making an AJAX request to fetch the initial items list itself. The WebDropDown control supports this, i think it makes sense for controls that don't have their items initially vizible on the client. 

I hope this helps,

Angel