Q&A: Why is it Office:Mac 2011 if it's coming out this year?

I got this one via email, and I've seen variants of it elsewhere:

i thought office was coming out this year, why is the name of it office 2011?

Our naming is like that of cars: if it comes out in the first half of the year, it gets that year; if it comes out in the second half of the year, it's the next year. The next version of Office:Mac is coming out for the holidays this year, so that's Office:Mac 2011.