Option 1.
Your Input Needed - Leaderboard Behavior

Post #8 should come with a public health warning. I'm not an epileptic, but just looking at the flashing clown makes me feel rough.
p.s. Why not have both options?
A yearly leaderboard would present issues at end of year as speed of play and sandbagging becomes a huge issue. For instance...if I want to be number one on a yearly board I could play many tounraments that begin now and slow my play down in those games I would expect to win. This would greatly affect my '09 results. If the system goes by start date of tournament then we would have to wait a long time to know who won for a given year.
Also to note if these boards is that hyper activity is over-rewarded. It may be worth considering the score being the 12 best results or something along those lines so that the leaderboards reflect the best players and teams and not simply the most active.
Pro Tennis, as I recall, is under such a system (rolling and weighted) that appears to work pretty well.
Just some thoughts.

In addition to "this year's leaderboard", a "lifetime leaderboard" is also a niec feature, why not have both?
And can we have other stats on a more recent basis too? Like avg. opponent's rating for the last 6 months, etc.

I like the idea of option 1, and this is why:
If you just want to be able to award trophies, you can still give a trophy every January 1 and it would be the same as if you were using option 2. But I think it will be fun/interesting to watch the ebb and flow of your points just like we watch our ratings in online chess.

This is much needed today! I'd take any one of these over our current system, but No. 2 is my favorite. Maybe we could just do both
We have a few "leaderboards" now on Chess.com. They are:
There are two ways we could make these leaderboards behave. I've given both options below with some thoughts behind each. Please post which one you think you'd like more. Please keep your posts short unless you have other pros and cons you'd like to add that haven't already been given.
OPTION 1: ROLLING LEADERBOARDS
This option gives us leaderboards which update daily and recalculate points based on the previous N days (probably 365 days). So, the leaderboard is always a snapshot in time of the players (or teams) with the most points in the last year.
This option means our leaderboards will always be somewhat meaningful and reflect performance over the last year. Your points will never be "reset", you'd only slowly lose points as your points "expired" out the backend of the rolling period.
OPTION 2: YEARLY LEADERBOARDS
With this option, our leaderboards would RESET on January 1 of every year. You would be able to view past years leaderboards. We might also do something where the top 10 finishers on the leaderboard are awarded a trophy like "1st Place - Chess.com Tournament Leaderboard (2008)".
The downside to this is that people joining the site midyear or late into the year wouldnt ever really have a chance of placing high on the leaderboard for that year. You also have to "start over" each year with 0 points all over again. This might be frustrating to some players. Due to the length of the bigger tournaments, a tournament may finish on Jan 10th and count towards 2009 but 90% of that tournament was played during 2008.