Consensus in this case = no economically-significant opposition, not majority support or whatever. There is still significant opposition, so there is no consensus. (BIP 101 is very strongly opposed by many experts, so if consensus on BIP 101 is possible at all, it won't happen with any speed.)

As I've mentioned previously, Bitcoin would need to be redefined to equal XT before XT would be allowed on /r/Bitcoin, bitcointalk.org, and bitcoin.org. Without preexisting consensus, this'd require that some big chunk of the economy actually diverge from Bitcoin and that their altcoin succeed in overtaking the vast majority of the economy. Those companies are significant (and I am very disappointed that they are acting so irresponsibly), but their "votes" right now are not especially meaningful -- none of them are going to actually move to an altcoin that few of their customers and partners support, no matter what they say now. If I was sure that they would stick strongly to the XT "suicide pact" (perhaps due to a legally-binding agreement), or if they started pushing XT to their customers, then I would classify these companies as altcoin companies and treat them as such.

In other words, without consensus, XT needs to utterly defeat "old" Bitcoin (including bitcointalk.org, etc.) on the market before I could recognize it as Bitcoin. This is messy, but it's the only reasonable approach as far as I can tell. It's not reasonable to go along with what a handful of what are essentially banks say we should do -- that's the sort of thing that Bitcoin was designed to stop.