The addition of ten new members to the European Union has added nine languages, for a total of twenty. That makes 380 language pairs. For many of them, it is going to be hard to find translators and interpreters. How many people, for example, can translate from Latvian into Maltese? According to this article in today's New York Times, the EU is now looking for translators and interpreters for the newly added languages.
You might think that, at least in writing, the problem would not be so bad because machine translation can be done by means of an intermediate representation independent of the particular languages. In this case, adding a language means adding translation between that language and the intermediate representation, not adding translation between the new language and all of the other languages. Such interlingual machine translation systems have been studied for many years, but the dominant view still favors transfer systems, in which languages are translated pairwise in order to take advantage of detailed knowledge of the correspondance between the two languages. The MT system currently in use by the EU is a transfer system. According to this report [PDF document]], that is what it expects to continue to use for the forseeable future.
In speech, the need for interpreters is reduced by the fact that most EU politicians and staff speak English, French, or German, with English now the dominant language. According to the New York Times article, more than 90% of European highschool students now study English. French is studied by only 29 percent in Germany, 27 percent in Italy and 24 percent in Spain. German is still widely studied in Central Europe, but is studied by only 31 percent in France, 8 percent in Italy and 1 percent in Spain.