Tecmo's told Eurogamer that Dead or Alive: Paradise will be released on 2nd April in Europe.
There won't be a demo, but there's a meaty (fleshy?) trailer that should give you an idea of what to expect.
DOA: Paradise transports girls from the fighting series onto an island in their bikinis. There they play volleyball, go to casinos and pose for photographs. It's all a bit steamy - but not degrading or soft porn-like, apparently.