I dunno.
Jimmer's game was more distinct - Jeremy Lin is a good traditional D'Antoni point guard, whereas Jimmer was a bit more unique in that his range and ability to take over games seemed freakish. On the other hand, Lin's doing this on a bigger stage, and in the greatest basketball arena in the world. And he doesn't suffer from the same obscurity problems that Jimmer faced - he's actually on TV, and his games aren't mired in the same apathy that follows regular season college hoops. (I know the NBA takes a while to heat up, too, but a substantial fraction of fans don't even follow NCAA hoops until tourney time.)
I also wonder how much Jimmermania is tainted by his NBA struggles.
If we frame it in Lin's pro career vs. Jimmer's college career, my gut feeling is that Jimmermania will have the better ending - Jimmer was a phenom his entire senior year, while my guess is that Lin will become a great, possibly all-star, PG - but will probably not rise to Stockton/Nash/Paul levels. Jimmer was a college equivalent to a all-timer like Stockton/Nash/Paul (even if his game was way different than those three guys).
Aside from comparing the two, I have to admit - I've been reading a lot of columns from Asian-Americans about the pride of seeing one of their own performing at such a high level, and it reminds me of a lot of the pride I personally felt during Jimmermania.