Everybody and their brother celebrated the turn of the century in the year 2000, and everybody agrees on this being a new decade except for the nerds. ;)
I forgot to include that Directed Edge will have a turnover bigger than Google by 2011, sorry :)
Only if by "technically" you mean "equally arbitrary". (Unless you have a good reason why we should take Gregory XII's 1582 papal fiat that gave us our baroque calendaring system to be less arbitrary than demarcating decades by years that end in zero.) While your at it, I'm curious why we should consider the years 2 through 1581 to be more "real" than the year 0: that is, if he could retroactively name them by decree, why can't we just establish a convention that the year 0 === 1 B.C? It's not like doing so would destroy any elegance the system might have.
There was no Gregorian year 1, 2, 3, 4, 5, 6, ..., or 1581, either. There is no contradiction in the calendar starting on a 1 but decades starting on a 0; either way the calendar actually started in the middle of a decade/century/millenium. True pedants should be insisting the decade starts on a 2, and centuries start on 82s!
You might have a point if the discussion mentioned the "second decade of the twenty-first century." A contiguous ten year period is a decade. Decades start and end all of the time without requiring nerd approval.