If you're one of the unfortunate MacBook Pro owners plagued by a stalling and clicking hard drive, then you're in luck. Apple has stated that MacBook Pro models with malfunctioning 7200RPM 500GB hard drives are in for a fix - and it won't require you to ship your laptop off.
Cupertino has reported to numerous sources that they have been working on a way to circumvent the problem, and the fix will come through a software patch. Anyone affected by the issue will know right away. Your hard drive will let out a clicking sound, followed by a stall which generally lasts about 10 seconds. It's not known to cause data loss or system lockups, and is more a nuisance than anything else.
The symptoms mimic what most know to be imminent hardware-level failure, but that doesn't appear to be the case here. Apple hasn't published a timeline for the fix yet, but given the benign nature, they probably aren't in a rush.