That's only if the IOC actually grants New York the Olympics. They've already said that if the new stadium isn't built New York won't get it but not that they will get it if they do.
If the IOC wasn't so notoriously corrupt, I might think it would be a good idea.
So if NY builds the stadium and then another city pays a bigger bribe to the IOC and they award that city the 2012 games... boom... the NY taxpayers take the shaft once again.
If the Jets want a stadium, they should build it in Queens or Brooklyn. I'd even support a $100M in state money to help build one on the island (one Super Bowl would pay that back), but the west side of Manhattan is just too expensive (and you couldn't tailgate there)