That's right, you can now setup multiple install locations on steam. Not to mention you can also sort through and see the installation size of all of your hardly played games.
Here is how you go about doing this.
- Make sure you have the Beta client installed
- Start Steam with -dev AKA create a shortcut and change the save target to look like this
D:\Steam\Steam.exe -dev
- Go to console and type install_folder_ui
- Add other folders as needed that have the space you need