Re: My money's on Vodafone being the first to start charging
It's interesting to see what's happening in France recently. All the cellphone companies have started adding 'extras' to phone contracts, for which they increase the monthly charge. Things like "TV on the phone" or "data allowance increased from 4GB to 10GB", which many people won't either use or care about. They advertise it as "better value" to justify the price rise, but in the small print there's often a note that says you can refuse the new feature but the price still goes up. They are also all hiking their roaming and call charges for non-EU countries. All predictable, they need to keep their margins up now that they can't (over)charge for EU roaming.
My bet is that some UK operators will start offering cheaper contracts without free roaming, probably pushing them as "domestic" or "all-Britain" or some suitable marketing fluff. They'll wait and see how popular they are with the large number of folks who never go abroad, and once they've got plenty of people to shift they'll rebadge the older contracts as "professional" or "frequent traveller" ones, and increase prices all round.