According to the Daily Yomiuri, some schools are postponing foreign trips in light of the influenza, but not very many have done so at the moment.
Schools postponing foreign trips : National : DAILY YOMIURI ONLINE (The Daily Yomiuri)
However, the same article confirms that Japanese students have now contracted Swine Flu, so you'll hardly be taking it with you.
The Mainichi Daily News has this amusing piece:
Japanese expats return from Mexico in droves due to flu outbreak - The Mainichi Daily News
I suspect anyone who's idiotic enough to fly home just because a few people in Mexico got the 'flu is probably likely to be idiotic enough to view you as a dirty, disease-ridden hafu who's come to tread mud through their house and drop litter on the streets. Naturally they're perfectly clean, so couldn't possibly have carried 'flu home with them, nooo
I particularly like this: "Currently, on-board quarantines are conducted for passengers arriving from Mexico and other countries that are home to swine flu patients. Those who arrived in Japan via a third country are also checked with health questionnaires. If a person suspected of infection is found, he or she will be isolated before going through disembarkation procedures."
Because sharing a flight with 400 other people then getting isolated on landing can't
possibly pass an airborne virus onto others
Basically you'll always encounter some people in any country you visit who don't want to talk to you. Why worry?