As if you didn't know what the spinning top ending really meant! Still, if there's a glimmer of doubt in your mind, check out what Sir Michael Caine says about it here. Requisite WARNING: SPOILERS alert is flashing red now.
Ok, so if you hark back to the ending, you'll remember Cobb was reunited with his children and father (Caine) in a sob-alicious final scene. As his usual style dictates, he spins the silver top to double-check he's back in reality, but doesn't care enough to watch whether it ever stops spinning (thus, representing he's in real life).
Caine let slip with the spoiler-goods when he appeared on BBC Radio to promote his autobiography. This is what he had to say about director Christopher Nolan's ending:
"[The spinning top] drops at the end, that's when I come back on. If I'm there it's real, because I'm never in the dream. I'm the guy who invented the dream."
There you have it, final confirmation the ending was exactly what you suspected. I still maintain my stance that Nolan should've done a Ridley Scott and filmed several different endings to puzzle us with—or that Caine's character should've placed his hand on the spinning top, breaking the motion himself and denying us the chance to see it wobbling slightly. Also, he should've kept his piehole trap-door shut too. [BBC via ScreenRant]