2018 began with only about 10% of Bitcoin transactions occurring with SegWit, but with more and more exchanges and wallet services implementing SegWit transactions for Bitcoin on a weekly basis - the number of transactions are now nearing 40% - according to Transactionfee.info (link).

SegWit is viewed as the scaling solution Bitcoin needs - increasing the block size and thus the capacity of the network. Although many say this is a solution that does the trick for now - but long term if Bitcoin is to be used as a currency by millions, another solution will be needed - which is where Lightening Network could step in.

We could be soon hearing the news that the majority of Bitcoin transactions are on SegWit - as we should cross that 51%+ point within a few weeks.