I don't know what you saw but the series(3) is finished and there will be no more. Not with present cast anyway.
I believe the entire 3 series will be repeated soon on BBC 3 or 4.
I agree it is very good piece of TV drama.
Mr Q and I only started getting in to Wallander on the last series so we're looking forward to seeing the first two. Saw the Branagh versions first which were ok but the original swedish series is so much better!