Looks like plain old Aero to me.

There is a tab in Windowblinds called "Transparency" where you can adjust this to your desires, therefore you could make any WB completely transparent.

Have you looked at the Naked or Naked Noir themes by vStyler?

These WB's are not Win 7 compatilble

And the transparency option in WindowBlinds is not what i'm looking for...

try out butch's wb's ..... most of them are by default transparent !!

It does look like that only the Aero blur is disabled.  I've been checking around and the Windows 7 release client had the ability to turn the blur on and off.  Now, apparently, you have to re-write a registry key to do it. http://www.themobicrunch.com/2010/05/remove-or-stop-the-aero-blur-effect-in-windows-7-how-to#more-7943

In Windows 7 got to Control Panel\All Control Panel Items\Personalization\Window Color and Appearance

click enable transparency, choose the clear color (bottom right)and slide the color intensity all the way to the left

clear windows aero with blur off like shown above

The blur is still there after that, but thanks for the reply Lantec

Elemental Air by 1MrPaul1 also works pretty well with 7 Xtreme.

Clear Vista by Butch123 comes close, and works ok with Win7.