Back in October 2015 an EU ruling took place that by next month (April 2016) there will be a cap on mobile roaming charges while travelling in the EU. Additionally by June 2017 roaming charges while in the EU should be dropped altogether.
This is great news and long overdue, however, it is still unclear how mobile operators are going to make up the shortfall in revenue which they used to get from expensive roaming rates. Some have suggested that this will mean that general rates to everyone will increase for travellers and domestic users alike in order to comply with the directive, others say that this will create volatility in the market through acquisitions and increased competition while network providers scramble for the ever elusive increased market share.
One thing is for sure, mobile networks won't go down without a fight and they will be trying to claw back that revenue one way or another. Watch the next year with caution especially when it comes to selecting the right mobile provider.