As Axel H. Horns earlier mentioned in his post, the London Agreement enters into force on 1 May 2008. Now the EPO finally updated their information on the matter, see http://www.epo.org/topics/issues/london-agreement/implementing.html and http://www.epo.org/patents/law/legislative-initiatives/london-agreement/key-points.html, including specifics on the relevant countries. In short, the current status is:

The countries not listed below, still require full translation of patents into a national language, as usual! 

Apart from the translation of the claims into all 3 official EPO languages (English, French and German) required by the EPO for issuing a European patent, no further translations are required for validation in France, Germany, Liechtenstein, Luxembourg, Monaco, Switzerland and the United Kingdom.

The following countries only require translation of the claims into a national language: Latvia and Slovenia. 

The following countries require translation of the description into English and the claims into a national language: Croatia, Denmark, Iceland and the Netherlands. Furthermore, Sweden is expected to join this group before 1 May 2008.

The London Agreement is optional for the old EPC-member states, so there is no guarantee that all states will ever sign the agreement. Has anyone got word about the intentions or thoughts in the southern European countries, for example?

The London Agreement is not optional for new EPC-member states.

In the United Kingdom, Switzerland and Liechtenstein, the translation requirements have already been dispensed with as of 1 February 2008.