As of today, Bitcoin Improvement Proposal 91 has sustained the necessary 80% miner support for enough time to officially lock in. With that done, the path to full activation of SegWit has now begun.
BIP 91 has been activated as part of a wider and controversial effort to increase the blockchain’s transaction volume called SegWit2x. It was originally planned to be activated later, but the effort was accelerated to avoid a possible split in the blockchain caused by the activation of node-operator focused BIP 148, which is set to activate on August 1st.
Even with SegWit support now locked via BIP 91, there are still other steps that need to be taken and possible hurdles to overcome before full SegWit activation is achieved. There is a “grace period” of about 2.5 days to allow miners to prepare for the change, and SegWit itself won’t fully activate until the next difficulty adjustment period, which will take about 2 weeks. There have also been concerns from some in the community that the miners won’t actually follow through on their promise to support SegWit, since support for the original BIP that introduced it has stayed relatively low. Bitcoin developer Peter Todd did a post on Reddit that expressed this concern, and also pointed out that the number of nodes running software needed to support BIP 91 isn’t very high.
Many say these concerns are unfounded though, given the amount of effort put forth by both miners and developers to get everyone on board with BIP 91. The very real threat of a split in the blockchain created by the activation of BIP 148 is also a good reason to believe things will go smoothly. Only time will tell, but right now it looks like SegWit is coming.