[inquisitor]

This article omits the probably most exciting proposal of Neelie Kroes' recent foray, which also intends to allow consumers chosing an alternative roaming provider while keeping their original SIM card and phone number:

Originally Posted by http://europa.eu/rapid/pressReleasesAction.do?reference=SPEECH/11/502&format=HTML&aged=0&language=EN&guiLanguage=en

On the demand side, we want to give consumers more transparency and more choice. Our proposals would offer them the right to choose an alternative provider for EU-wide roaming services, benefiting from lower prices, while keeping their usual provider when they're at home.

If people do opt for a separate roaming contract, the phone will automatically switch to their pre-selected roaming provider when travelling - using the same phone number and without changing their SIM card every time.

and

Originally Posted by http://europa.eu/rapid/pressReleasesAction.do?reference=IP/11/835&format=HTML&aged=0&language=EN&guiLanguage=en

Letting consumers choose an alternative provider for roaming services, irrespective of their national provider. Each time the customer crossed a border, they would automatically switch to their chosen roaming provider, without any further action on their part, while keeping the same number and subscriber identity module (SIM card). This would enhance transparency and allow customers to shop around for the best roaming offers and encourage operators to offer more competitive roaming deals.

and

Originally Posted by http://europa.eu/rapid/pressReleasesAction.do?reference=MEMO/11/485&format=HTML&aged=0&language=EN&guiLanguage=en

How would people buy a separate mobile phone roaming contract?

As of 1st July 2014, all EU customers would have the option to sign up for a mobile phone roaming contract, which would be separate from their contract for national mobile services, while keeping the same phone number. Consumers would not be obliged to do this; but some mobile phone users may find that a different operator for roaming would offer more interesting prices or deals.

Mobile phones operators would have to inform their customers from 1st July 2014 that they had the option to buy a separate roaming contract.

From that date, if you took out a new domestic mobile phone contract, you would also at the same time be able to select a separate mobile roaming provider.

The additional competition brought through this measure would generally bring prices down, so that consumers who do not choose to buy a separate roaming contract would also benefit.

I really like this idea of virtually opening the SIM card to third party providers. Actually there are already similar solutions in some countries like Saudi Arabia and Mauritius, where inbound roaming customers may subscribe to a prepaid plan of the local MNO using their existing SIM card. After subscription and topping up credit (with local topup vouchers of course) roamers can call at the local MNO's rates (deducted from the local prepaid credit) and will be assigned a local number. While this sounds pretty interesting, I think this involves some legal and technical problems. First of all roaming agreements between operators surely prohibit such "hijacking" of customers and secondly bypassing the home operator (and issuer of SIM-card) may have an impact on the authentication process, which is performed between the SIM-card in the mobile terminal and the AuC (= authentication center, usually integrated in the HLR). At least there won't be any encrypted communication without access to the HLR (this is an issue in Lybia where rebels have separated GSM networks and "hijacked" customers, see Free Libyana: Gadaffi networkjacker speaks! ? The Register).
With Neelie Kroes' help these issues will of course be solved. However from my understanding the EU intends to establish firm roaming providers you would subscribe to and who will permanently provide roaming service throughout the whole EU. This would mean people would again have to struggle with different operators and do paper work to switch operators, which would slow down competition. I would rather prefer if people could chose a provider each time they visit another EU country. There should be an APN (access point) and webserver reachable from every EU network free of charge, through which roamers can check and chose a provider and tariff and all the usage would be billed either by credit card or by the home operator.
If this will become reality there would be no need for capping tariffs because competition would drive down prices significantly below those proposed rates.