https://www.extremetech.com/internet/254280-two-weeks-later-bitcoin-forking
excellent article...

On Github(i heard he just got removed after this, check his twitter),
 Jeff Garzik writes:

    Segregated Witness support has been locked-in as a soft fork expected to activate around August 23 2017 (block height 481,824). Bitcoin clients that are not currently SegWit-compatible and wish to benefit from the new type of transaction must perform extensive upgrades to various subsystems, including changes to transaction serialization, signature hash computation, block weight calculation, scripting engine, block validation, a new address scheme, and P2P protocol upgrades. Fortunately Segregated Witness compatibility is opt-in, and existing Simplifed Payment Verification (SPV) wallets and full nodes are expected to continue working without changes after SegWit activates.