I actually agree with everything you just said. The idea here would have to be a swipe in from above the screen to open the panel, kind of like it's currently implemented in Mountain Lion's Notification Center, where you swipe from outside the touchpad from the right to open it.I don't quite get it...are you swiping up or just tapping on the top?
I kind of prefer the current way mainly because there isn't really any reason to leave part of the app showing if you can't interact with it. Also if it is a new gesture it could interfere with the currently running app...
Personally I want the canvas material background gone, swipe to dismiss and context aware app widgets (Music controls when a music app is running, runkeeper stats when RK is running, download info if you have an app downloading something in the background, timer widget when you set a timer, etc.) That would be the ideal notification center in my opinion.
Plus something better than the 20 pixel clear button that never works on the first tap...and then you have to hit it a second time.