I've made a nice app to install widgets easily on Samsung TVs.
All you need is to place widget .zip files to "widgets" subfolder located in the same folder where application is saved. The application will automatically scan all folders and files within "widgets" subfolder and list only Samsung widgets with their icons and descriptions. You can then decide which one you want to install to your TV by selecting them using checkboxes.
After you have selected which apps you want to install, you need to login with "develop" account to your TV and enter development menu. There you need to change IP address to the IP address displayed in the application (it's actually your PC LAN IP address). Then you select option to sync and that's all ! You might need to exit Smart Hub and enter again to see new apps.
Important: If Windows prompts you to allow application in firewall, you need to allow it for your local network so your TV can talk to it.
Here's a screenshot of the app:

Download link, updated to v1.1: P.S. This app is Windows only but I can compile it for Macintosh and Linux (Ubuntu for example).
If you have some ideas how to improve the app, please leave comments. Report any bugs as well.
The app is tested only on D7000 TV, but should work on any newer as well.