Yes, according to Alan Sepinwall, Wilson will be back. The producers like the rel'p between him & House. His absence will give them the opportunity to build up the character of the P.I., about whom they are planning a spin-off. He's supposed to be just like House: curmudgeonly, cynical, smart, compelling/repulsive. Like PITA P.I. House instead of PITA Dr. House.
Oh, Wilson will be back. Just like how Chase, Cameron and Foreman came back. I would like to see more of Chase and Cameron even though I like the way they gave them their own lives in different parts of the hospital.
Poor Wilson just needs time to grieve and get his bearings straight again.