What is the current status of the anomalous  muon magnetic moment? Many years ago, a discrepancy was found between the experimentally measured value of the muon magnetic moment, and the theoretically calculated value. Shockingly, most physicists were blase about it. It was no big deal to them. They dismissed it as either an experimental error, or some mistake in the QCD calculations, even though error bars have been painstakingly computed for both of them, and the discrepency still survived up to a few sigmas.
What is the current status of the anomalous muon magnetic moment?
 A: One can find a number of references by googling. Here is one:
http://arxiv.org/PS_cache/hep-ph/pdf/0102/0102122v2.pdf
The discrepancy between measurements and standard model calculations for the muon anomalous magnetic moment  is of the order of 2.6 sigma.  There are interpretations that this is a signal for new physics.
If you look at the discussion of standard deviations needed to declare a discovery in particle physics you will find that 5 sigma is really necessary. 2.5 sigma is barely at the level of "interesting" That is why there is not much discussion and you observe :

Shockingly, most physicists were blase about it. 

It was no big deal to them except :interesting, more data needed.
If it were 4 sigma, they would be jumping up and down with excitement and speculating about the masses of new physics intermediate particles.
An example is the accurate data from LEP that allowed to calculate the top mass, before it was observed at Fermi lab, from differences in expectations.
A: WP Anomalous_magnetic_moment_of_the_muon 3.4$\sigma$ standard deviation (as of 2007) 

is a contribution of effects of
  quantum mechanics, expressed by
  Feynman diagrams with loops, to the
  magnetic moment of that particle.
   ...its measurement provides a precision
  test of the Standard Model.

The experiment Home Page - E821 Muon (g-2) (as of 2004)
Overview of the experiment
Improved predictions as of 2007 : 3.4$\sigma$ :
Abstract

We update the Standard Model
  predictions of the anomalous magnetic
  moment of the muon..., incorporating
  the new $e_{+}e_{-}-> \pi\pi$ data
  obtained by CMD-2 and KLOE, as well as
  the corrected SND data, and other
  improvements. The prediction .. which
  corresponds to a 3.4 $sigma$ 
  deviation from the measured value...

But the final Note added in proof:(page 10) points to 3.5$\sigma$ discrepancy
Future Experiments 
I will take this fact in consideration when I read that SM is OK.
(there is a particle model by Douglas Pinnow (Our Resonant Universe) waiting to be read and commented. Have a glimpse of it here)   
EDIT add
IMO, add: In the experiment the muons are obtained by p+p collisions; add: the proton 'spin crisis' antiquity; then the model defect hypothesis is enhanced. (both problems are linked, I think)  
