Codemasters is busy teasing Overlord 3, tweeting an image of the series' villainous protagonist's trademark helm, and setting up afor the venerable Minion Master
Right now someone from Codemasters is simply having fun messing about on that account by tweeting in character, but more information is almost certainly on the way.
Overlord is something of a cult series, a mix of third-person action and mild RTS elements that started off back, with a sequel following on in 2009. It's been a while since we've heard anything regarding the franchise, which while moderately successful was never a particularly big seller, so a lot of fans had simply assumed it had gone the way of the dodo.
It'll be interesting to see whatcomes up with using today's improved tech. More info as soon as we get it.