New Year's Day is a happy occasion because we got a new 4-digit year to use for the next 366 days, until we get so sick that we look forward to using another 4-digit year.
To many people, it symbolises a brand new start on things that they can't wait to abandon or reset, for instance, a bad academic year, or a bad sales target year.
To the ethnic Chinese, 2008 has an auspicious ring to that because of the digit "8" which infers prosperity.
But then I suppose to some people, abandoning the old year isn't a good thing too. To some people, the old year is a stellar year with great achievements and accolades. All these good things will come to pass and put aside in the new calendar year. You might be the employee/student/top-scorer of the year in 2007 but that means in 2008 you would have to start all over again to earn that title. In other cases, you might not have been a good performer in 2007 and with the passing of the year, the scores are tallied and it's not up to standard. If 2007 were to go on and on, perhaps you might do better and demonstrate better results for the calendar year.
So, should it be a happy new year afterall? To me, it's just another new year. Everyone loves new things, but after first week, the hype will cease. 2008 will just be another calendar year, as always been for the past 2007 years.