I just sat my interviews at the end of november, and past. The technical wasnt as technical as i thought it was going to be. There were a number of laminated sheets with different problems on them. For example there was a map with an aitport on it and i was asked what problems the surronding area would cause. In another i was asked about QFE and QNH. I was also asked how ILS, VORS and INS works, but i think i was asked about INS because of my degree. I was also asked how i would react in certain situations, ie i saw an older ATCO about to make a mistake etc. He also asked about me and what i liked. All in all the person who took the interview was a perfectly nice chap and i thought it was the easyest interview of the day, but the it might have been my background that it allowed it to be.
Best of luck