Highly unlikely that you'll get to double dip. AC will likely do a sweep at the beginning or middle of December to see who has already qualified for 2011 status. If you have already qualified for a level, you should receive an email to select your benefits. The exception is if you are close to the next level; in which case they will likely hold off on allowing you to select your 2011 benefits to see which category you end up qualifying for.

If you will have 99 segments by December 3, you will show up as SE when they do the sweep (btw it is only 95 segments to qualify for SE).

Now, if you were only going to have 75 segments by the time the sweep takes place, AC would likely give you Elite status and allow you to select the benefits. If you had 20 segments post from the time of the sweep until the end of the year you could probably double dip (but with the introduction of ecerts pending this year you would likely not be able to double dip anyways, unless you were selecting things such as lounge guest passes).