It's already been done:
The "I have NO 3rd gear problems" List/thread
For a little comparison, here are the people on this forum who have participated, who DO have a problem:
The "I have a 3rd gear problem" List
While no one has any idea or way of knowing what leads to a good transmission in this car, there are those who do have the problem, and those who do not. On a global scale, no one knows.
The 2008 models will be no different than the 2006 or 2007 models. This "fix" that is allegedly coming out for the Si transmission will replace syncros and detend/detent (sp?) ball springs. We do not have an estimated or proposed date for this. Rumor has it that Honda is holding off releasing the fix until they have enough parts for the dealers, which tells me it is quite a big deal.
My suggestion would be to get the Si, and swap your MTF to Amsoil or GM Syncromesh as soon as you can. No one knows whether or not an early swap can be primary prevention (prevent it before it becomes a problem) or whether it is tertiary protection (after the damage has been done, preventing any further damage). Most users report that it almost all but eliminates transmission issues if you switch, but it is NOT a fix.
We have not had any "studies" done to see whether Amsoil, when used at the beginning of the cars life, can prevent the problem from occurring. It is safe to say however, that after the problem occurs, for whatever reasons, Amsoil is nothing more than a band-aid solution, albeit a worthwhile one.