DailyTech Blogger Michael Asher sees through to the nub of significance within Steve McIntyre's discovery of errors in the GHCN weather data:
The effect of the correction on global temperatures is minor (some 1-2% less warming than originally thought), but the effect on the US global warming propaganda machine could be huge.
In other words, Steve's achievement is a propaganda victory (for the forces of climate change skepticism) more than a scientific one (which is not to dispute the fact that McIntyre's work has uncovered a real error in GHCN collection procedures).
Incidentally, it is disingenuous to, as some media outlets have, refer to this error as a result of the Y2K bug. McIntyre himself writes:
By Y2K problem here, I don’t specifically mean that the error is due to 2-digit date formats, but that the error, whatever its source, is observed commencing Jan 2000.
Or at least there has been no evidence provided yet that the error was caused by this specific bug.