If you are interested in programming in Visual Basic.Net using DirectX, and arent keen on waiting for the GDK.NET product to be released, Microsoft has a great resource for their dotNet stuff at
CODING 4 FUN @ MSDN
http://blogs.msdn.com/coding4fun/archive/2006/11/02/938703.aspx
The Above Tutorial is an Introduction to programming in DirectX 9 using the dotNET environment, specifically Visual Basic and Visual C#.. It is a great intro to all of the basic elements of hooking into directX from a managed code app, covers everything from creating devices, terrain, 3D object manipulation to DirectSound sound implementaion.. The series of tutorials is rather long and if you dont already know the language/s quite well, may be beyond the abilities of a beginning programmer, however by then end of it, you will have created a fully working native managed directX 9 3D Game, albiet without alot of polish, but the basics are there...
Ok, now, im sorry if I may have misunderstood your question, the above respone was for if you were asking from a programming point of view.... If on the other hand, by "drag and drop" 3D model creation, you mean the actual 3D object design itself, not the program, then you would be looking at an application such as 3DMax or Softimage XSI if u got some cash to burn, or something like Milkshape3D or a Host of free 3D Modelling packages you can find across the web by searching.
Personally im not aware of very many 3D design packages that come with "pre-made" model pieces that you can drag and drop to make a model, essentially, most 3D packages will give you a set of "Polygonal Primitives" such as cubes, spheres and plains, a bunch of "Drawing tools" for curves and boxes and lines, and a host of tools to manipulate those object in various ways, to make a 3D model.... I know there are a few slightly more "specialist" 3D packages available that are designed with specific pruposes in mind, such as just the UV Texturing process, or Animation of an already created model, again, I cant say for sure if there is a drag and drop model creator, however TGC do have quite a few products listed on their home pages relating to different aspects of 3D design etc... would be a good place to start looking. /plug finsihed.
If it ain't broke.... DONT FIX IT !!!