In these days I am exceeding with exclamation marks but let me say that there are sound reasons for this. I will keep on staying on a prudence line as my more renowned colleagues are doing but there is a talk by Giovanni Punzi, the spokesman of CDF Collaboration at Tevatron, (see here), presenting the following picture
They increased the number of events and the bump is still there. They have consistently found for the mass of this presumed particle. Of course, we have to wait for D0 and LHC to confirm this finding but this is becoming more and more a real discovery. But since the first inception, theoretical physicists have come out with possible explanations, the most reasonable of these seems a new U(1) interaction with Z’ leptophobic boson, where leptophobic just means that this particle has essentially strong decay modes. People at CDF has discarded several possible mundane explanations that emerged at the dawn of the first announcement but, as my readers know, it should be stated that our current understanding of low-energy QCD is somewhat in development and some modeling used by people at CERN or Tevatron can be not so accurate. My personal view is that is time to wait yet notwithstanding the good news.
Kingman Cheung, & Jeonghyeon Song (2011). Baryonic Z’ Explanation for the CDF Wjj Excess arXiv arXiv: 1104.1375v3