The developers of Bitcoin Core, the official Bitcoin client, refuse to include the SegWit2x code in the current protocol. The announcement is posted on the official Twitter of Bitcoin Core:
The Bitcoin Core project rejected the pull request for NYA "segwit2x" https://t.co/t8d8BHFSCX
— Bitcoin Core Project (@bitcoincoreorg) 28 августа 2017 г.
Thus, Bitcoin Core references a page on github.com which contains a request to include the SegWit2x code in the current protocol in order to make both versions compatible.
Bitcoin Core developers on reddit.com
Earlier this month, the Segwit2x developers team confirmed that the Bitcoin upgrade is to happen at block 494,784. However, it is emphasized that this code, although including the support for Segregated Witness, will be incompatible with the current version of Bitcoin Core.
It's also noteworthy, that last week, the Bitwala platform team announced its refusal to support the expected hard fork. The representatives noted that while signing the so-called New York Agreement, they did not know that it was accepted without the participation of the Bitcoin Core developers.