Europe is populated far more densely than the US and there is plenty of competition in individual markets (e.g. Germany), so I doubt that this will slow down competition.

What I really hope it will achieve is abolishment of roaming in any particular form – I have a German contract with German O2, currently stay in the UK and am usually logged in(?) to O2 UK’s network. Yet this is ‘roaming’ and forces me to pay more for calls, while paying less for texts (€0.1 per text by EU regulation rather than unregulated €0.19 at home).