Next big thing would be acceptence of Bitcoin and other crypto coins on a real-time basis which is bit difficult due to volatility, developers should focus on how to make cryptos usable like any other online payment method or the purpose it's developed instead of just leaving it as a investment medium because the core objective of crypto coin is to make our lives easier and upgrade ourself with next level of technologies which is need of the hour.

I feel Bitcoin and other altcoins needs to focus on adaptability by having tie up with tech startups and gradually move on to wider range of audiences.