EU players will soon be transitioned to the service of ProSibien Games for SOE’s MMOG lineup. DC Universe Online (DCUO) and EverQuest II have posted advisories to remind players of the transition and to make sure that any needed steps have been taken for their accounts before the move. DCUO is advising players to complete any transfers before the June 28th deadline if they plan to migrate their accounts to ProSibien. An updated FAQ has also been posted on the EverQuest II website to help address any lingering questions before its transition phase begins on or around June 20th.

Since I've seen this question relating to accounts asked a few times I'll add a snippet from the updated FAQ.

I am a European player with an existing SOE account. How will this shift impact my account?

It won’t. You will continue to play with your existing SOE account.

Sources: EQII ProSibien FAQ, DCUO Announcement