There's been a lot of idle chatter about Anthony Gonzalez's return from a PCL injury lately. None of it has been based on anything other than conjecture. Let's take a look how other WRs have come back from similar injuries. Part of the problem is that this kind of injury is extremely rare. Most wideouts go down with ACL injuries. I could only find three receivers with PCL injuries. I can't confirm how similar their precise injuries were to those of Anthony Gonzalez. PCL injuries are not considered nearly as severe in the long run as ACL injures.
Roy Williams 2007
Williams went down with a PCL late in 2007 after putting up 64/838/5 in 12 games. In 2008, he played for the worst team in history before a midseason trade sent him to Dallas. His combined numbers were 34/430/2. His YPC in 2007 was 13.1 yards per catch. In 2008 with Detroit that number fell to just 11.9, but rebounded to 13.6 with Dallas.
James Jones 2008
Jones had 47 catches for 676 yards and two scores his rookie year (with Brett Favre). He suffered his PCL injury late in his second season (2008) after posting 20 catches for a 13.7 YPC average. He came back in 2009 and posted 32 catches for 440 yards (13.8 YPC) and 5 TDs. His numbers the year after PCL surgery were slightly better than the year he suffered the injury.
Sidney Rice 2008
Rice battled a nagging PCL injury in 2008, but I can't confirm that he had surgery. Surgery is rare in PCL cases, and often doctors prefer to let it heal on its own. His YPC dropped from 12.8 to 9.4 from 2007 to 2008. Last year (with Favre) it spiked to 15.8 YPC.
Willis McGahee (Fiesta Bowl 2003)
McGahee blew a PCL late in the Fiesta Bowl in January 2003. He was drafted, but missed his entire rookie season. He came back in 2004 and rushed for 1128 yards, 13 TDs, and a 4.0 YPC.
Reggie Bush 2007
Bush missed the end of the 2007 season with a PCL injury. In 2008, he saw his yard per carry, yards per reception, and punt return yardage all increase dramatically. He returned 3 punts for scores in 2008.
Prognosis for Anthony Gonzalez
Most signs point to full recovery of prior skills for players with PCL injuries. The best news for Gonzo is that he already missed a full year. There is every reason to expect him to come back at 100% of the player he was before, certainly by the end of the season if not right away. There are not nearly as many good studies done on PCL injuries like Gonzo's because they are not at all common. Full recovery for a normal person from a normal surgery can take from 1-2 years, but it seems that football players tend to be ok the season following the injury. It's hard to compare any of these players to Gonzo, because other than Bush, the other four all experienced serious changes to their offense that make it difficult to measure their stats.