The new .ευ, which is .eu in Greek, was launched by EURid on 14th November.
EURid has a dedicated page on their site that explains the various policies that apply specifically to .ευ. One key policy is that the scripts need to match, so you cannot register a .ευ with latin script.
So far there have been 476 domains registered in .ευ
Not all registrars will offer .ευ so the registrar listing on the EURid site will be updated in the coming weeks to specifically flag registrars offering the IDN script.