The official site of this series by Kentarou Miura has posted five new teasers. It hasn't exactly been revealed if the return of this anime will be in the form of a TV series, movie or OVAS yet.
The teaser trailers can be seen here:
here (opens in a new window)
You can also see them here in this very page:
Teaser 1:
Teaser 2:
Teaser 3:
Teaser 4:
Teaser 5: