The Verge forums user Sentry posted the concept art you see above for the (underutilized) iOS task switcher, and I think it's awesome. Sentry's vision adds a lot of worthwhile information to the multitask bar without sacrificing the clear layout.
The app thumbnails are great, but I really like the various controls for music, WiFi and Bluetooth. It's such a pain to have to dig down into the Settings app every time I need to switch one of those on my phone or iPad, and having them accessible with just a double-tap and a swipe would be excellent.
I already heavily use the audio controls that pop up when you double tap the iOS Home button while your device is locked, and sliding the
