In a little-publicised change to the regulations, duty free from the US is expected to be allowed through security in the EU from mid-April. But it will not apply in other direction - presumably the US does not trust the EU!
There are already bilateral agreements between the EU and Singapore and Croatia.
From the
European Travel Retail Council:
On 31 July 2007, the European Commission formally adopted a regulation that allows for the recognition of liquids bought in selected third country airports and the European Union will now be able to agree to accept duty free liquids from “recognised” countries as being secure, thereby allowing transfer passengers to continue their journeys without having to surrender their goods.
If the Commission is satisfied that the security measures applied in a third country in relation to liquids meets ICAO standards, the Commission can decide to grant exemptions. The first country to be formally approved was Singapore on 14 December 2007 and as from 03 January 2008 travellers from Changi Airport have not had to forfeit their duty free LAGs when passing though transfer security screening points at EU airports.
Croatia became the second country to receive EU approval and as from 20 August 2008 travellers with LAGs arriving from the six Croatian airports are now free to transfer at EU airports.
An agreement was finally reached with the US in January 2009 in a somewhat controversial move, as this decision is only one-way - limited to those passengers travelling from the United States into the EU. For outbound passengers from the EU to the United States, current restrictions on liquid purchases will continue to apply. The new arrangement for EU bound travellers from international airports in the US is anticipated to come into effect by mid-April.