rlange - 1:17 pm on Jul 7, 2011 (gmt 0)
I assume Google has started everyone at +1 and not 0?
That "+1" isn't the total number; it's just part of the branded image. You can confirm this by searching for "webmaster tools". If you log into WMT it shows as having 52K +1's, but the SERPs button still only displays "+1".
You will notice, however, that the number of +1's is displayed in grey text below the description. The result for WMT says "26,707 people +1'd this", which is only roughly half of what the widget in WMT is reporting, so the total displayed on the SERPs is likely not real-time.
There's probably also some sort of threshold that needs to be met before it displays those counts on the SERPs.