It was begining to topple. Yes it wobbled for an un-naturally long time but at the end it was certainly begining to falter. It would've been nice, however, if they had just shown us the damn thing toppling.
Well it was definitely about to topple early on, when we first see Cobb walk away from the table (because that was clearly a real spin done in-camera), but I never saw it wobble HALF as bad as that when we cut back to the table again. And I was watching pretty damn intently.
Unless you guys all saw a different print from me.
At the very least, we have to accept that Nolan wanted the scene to be read both ways.