Chaos- you are pretty funny. Of course we celebrate New Years. Just like many people do around the world. The business world is based on the year 2009 coming up, so that is what the world goes by now.
However, yes, there are different calendars out there (Really, you mean the one based on 365 days isnt the only one). Yes, I am sorry to inform you that before the Julian Roman calender, there were others. Lunar calenders, based on the cycle of the moons are older calenders, and some people use that calender. Which means why certains Jewish and other holidays are on different days each year. It is cool to know different calenders and dates.
Hey, the Chinese must be too good for it too, since they are based on a different calender too. As are many other people and traditions.
By the way, we use the Gregorian calender today around the world, which if you truly look at it, doesnt make a ton on sense (some months have 30 days, others 31, one has 28...), but that is a different matter.