Two comments:
  • I'm always careful when looking at a moving average, you have to apply a shift of 13 weeks (3 months) to the left because sliding windows are not centered.
  • there was also a plateau in may 2005 but the prices continued to increase afterward.
The way I see it, the 26-week average today is simply a representation of the past 6-months of prices and to some degree the cumulative effect of those prices on the economy.