Bitcoin Core will signal support for and recognise SegWit enabled blocks, amongst other additions. Depending on your stance in the max block size issue, you might like to consider using one of the other many bitcoin clients such as https://www.bitcoinunlimited.info/ which supports bigger maximum block sizes as a solution to the full blocks we currently are experiencing.
i remember that merchants have an impact as well maybe not directly but they will influence miners decision, if for example the majority go with a specific side, either way at some point miners will be forced to do a decision...