Sadly no. Even worse, it is vastly unpredictable due to consistency at different focal-lengths, aperture and focus-distances. For DSLRs and SLDs, the choice of lens greatly matters too.
A number of review sites have methodologies and quote numbers in ms or fractions of a second which gives one relative measure but it not easy to generalize. In other words, you may get measurements saying that camera A is faster than B, but in another situation it is the contrary.
For compact cameras, the few that use Phase-Detection like the Fuji F300 EXR have the lead, followed by bright apertures ones like the Olympus XZ-1.
Among DSLRs, generally the ones with faster continuous drive usually have a fast AF and price to match.
Finally for SLDs, Sonly Alpha SLT use Phase-Detection. The Nikon 1 V1 and J1 also use Phase-Detection and claim to be extremely fast, although I have not tried them yet - one should be arriving soon.