Change your password. The linkedin engineers have since implemented passwords with salt now. Use a strong password.
The hackers were looking for multiple uses of the same passwords by different people to identify particularly weak passwords. These will be distributed and used from now on as higher priority guesses in any dictionary attack to any password-protected system.
It's not specifically linkedin that was targeted but linkedin made two errors. The first was to have a vulnerability that allowed the hashes to be stolen, the other was not salting them. By not salting them, two identical passwords have the same hash.