Angelini's team is using the technique to print human blood-vessel and canine kidney cells. They've even tested making a replica brain out of hydrogel. However, so far, the gel is not organic, so it doesn't help keep the tissue alive, but it does give it structure and form.
The main problem at the moment with 3D printing organs is that they collapse before they're finished. But the gel can be used to add support to the structures. It's an incremental improvement, but an important one on the way to 3D printed organs.