They found his body several years ago, it was determined that it was highly unlikely he made the summit of Mt. Everest.
As far as I know they only found the body of his climbing companion not Mallory's. If the Mountain ever melts enough the secrets will be revealed.
I stand corrected, I just checked the web and they claim that was Mallory's body they found. I thought that at the time in 1999 they claimed they found Irvine's body.
The only proof was a name tag on the clothes that they belonged to Mallory, but could have been Irvine.
Like I say if enough snow ever melts the truth may be settled one way or another.