A concept video of what a unified Control Center and multitasking interface would look like in iOS 8 has been created by designer Bill Labus and posted by TheTechBlock (via Cult of Mac).
Apple introduced Control Center and a refined version of multitasking with the release of iOS 7 last fall. While an overhaul or unification of both is unlikely to happen with any immediate update to iOS 7, it is possible that Apple could make major changes in time for iOS 8, which will likely be released this fall.Unfortunately, I find double-clicking the home button to be irritating- there's a noticeable delay between the second click and the multitasking view appearing, and in my haste I often accidentally triple-click the home button, forcing me to wait while the OS bounces into, and back out of, multitasking. Control Center's bottom edge gesture is far faster and easier to perform, however as I said I do use Control Center frequently as well, so I wouldn't necessarily want to swap the two and use the home button double click to bring up Control Center.
Article Link: iOS 8 Concept Video Features Unified Interface for Control Center and Multitasking