Update [11:38am]: The signing is now official as per the team's press release.
According to Cap Geek the Toronto Maple Leafs have signed European prospect Korbinian Holzer to a two-year, two-way contract. The deal is expected to be similar to the one that Jesse Blacker signed this Spring. Hockey's Future has his as the Maple Leafs' 6th ranked defensive prospect. He's spent the past three seasons playing with the DEG Metro Stars in Germany's top flight league so he's been apprenticing against men. He was on the Germans Olympic entry in Vancouver and was also part of the team that finished fourth at this year's Worlds in Germany. It looks like Holzer had a pretty big role to play in the Worlds.
Vice-President of Hockey Operations Dave Poulin stated in an interview a week or so ago that Holzer was going to be with the Marlies next season but it looks like the deal is still not official since Cap Geek would have the details.
Here are a couple of profiles to get an idea of the kind of player that Holzer could become: