Is Cobb still dreaming?

There are at least three hints that make me believe that he's dreaming. The first one being that the top spins for quite a while in the end, 50 seconds with no "clear" signs of fading versus 22 seconds from start to end when Cobb spins it in Kyoto. One could argue that he spun it harder in the end, maybe even because of the excitement of making it home to his kids, but spinning for more than double the time and without showing much wobbling? It's an uncomfortably long spin. Secondly, on the plane when Cobb wakes up, neither him nor Saito are connected to the machine, so if they are in Limbo together should they not be hooked up to the machine when they wake up? Is it possible for them to finish a dream together without being hooked up to the machine? Obviously they would not want to be hooked up if Fischer where to wake up before them. Another hint is, how does Saito know the job is done after all he died before Fischer opens the safe? Silly tourist! I would have thought he'd need to see more concrete evidence at this point such as a News announcement stating that Fischer would break up his energy company. But as others have mentioned on this forum and others, I guess he took "a leap of faith" or he did it because Cobb reminded him of their arrangement and pulled him out of limbo (he was also responsible for putting him in limbo because of Arthur's poor research ).

Obviously it's meant to be ambiguous, but remember that the spinning top Cobb uses should not be considered his totem - it belonged to Mal. His 'real' totem is the wedding ring, which you need to follow during the film and it'll confirm what Cobb says - ''In my dreams, we're still married.'' Also, the spinning top never showed sings of wobbling if it was a dream (ex. when he puts it in the safe while in Limbo with Mal). And than there's that he sees his children's faces for the first time, etc. etc., although someone might say that it's the catharsis he went through while on this journey [through the dreamland], but personally, I disagree.
As for the waking up in the plane without the Pasiv Dream machine, when they're being hooked up, they're basically drugged, so we could go on explaining to ourselves that they showed signs of waking up, and were disconnected, while fully waking up later - but it doesn't change the fact that it's unclear and should probably be that way. That's why Cobb and Saito feel their wrists after waking up. Nice find though, haven't thought about that before.