Please accept our apologies for the late reply, it is due to the release of Sitefinity 3.1.
It is possible to provide a custom user interface for the generic content control, you can use this technique
An easier way to customize the generic content editor is to configure the RadEditor that is used. The template for the generic content editor is located in Sitefinity\Admin\ControlTemplates\Generic_Content\EditorTemplate.ascx. To manage the RadEditor to fit your taste, you can see its online documentation
However, I don't think you should use generic content for only storing specific data as videos, or shockwave files. A more consistent decision would be to create a simple custom module for each type (i.e. Flash Animations Module) that processes only that kind of data. Then you will have to define your own controls for presenting and uploading such files.
I hope this information will help you solve the problem, if you have any other questions please contact us again.
the Telerik team