Is a corrupted HD a sign of something ominous for the hardware? The Verify Disk functionality of the Disk Utility reports that my HD is corrupted. I fixed the problem using the startup CD but what does that mean for the health of my HDD?
One time error usually means nothing.

Do use it as a warning - keep your backups current and perhaps even test a restore. Also, you might check things in a week to make sure it's not a sign of hardware errors instead of a software error.