As soon as Firefox started grabbing market share, Google backed them and at the same time (probably) started the process of creating Chrome. IE is one of those zombie things that's still around that does not matter. Arguably it's a nuisance even to MS at this point.
But IE didn't just become irrelevant overnight. It took antitrust enforcement and multiple massive companies pooling their resources to dislodge it from it's position. There was a significant, concerted effort to knock out IE, and I just don't see the same going on vis-a-vis Chrome now.