IMO this is the first real test of nakamoto consensus, and I don't really see a failure scenario as many are predicting. Worst case scenario is that the network splits into two coins. One with larger blocks and one without, and I would not consider that a failure because the split in consensus would be so great that the only solution would be to split the network and allow individual users to follow whichever fork they like. The other scenario is for a supermajority to be found through nakamoto consensus and that system survive as bitcoin.
I predict we will quietly see blocks larger than 1 mb appear after the first of the year and no damage will have been done.