Ourobotics is an Irish company that is developing bioprinters. They published an open source low cost bioprinter based on some standard RepRap parts named Renegade that can be sourced for some 900 USD. I doubt that someone will 3d print a kidney on it in a home workshop but some interesting biohacking project could come up in the future.
Ourobotics also developed high-end bioprinter that can print with 10 materials, has enclosed warm chamber for keeping the cells alive and costs some 12500 Euro.
... here it is printing an ear:
PDF with build instructions based on a common RepRap:
More detailed article about the project: