The Tech Report's attempts to test SSDs to destruction have hit the 500TB mark, with three two-bit MLC NAND drives and one three-bit TLC model all trying to survive.  They are using raw SMART data to keep track of sectors reallocated from the spare area to replace flash which has died due to repeated usage.  So far the Samsung 840 with its three bit TLC has suffered the most loss of sectors but like the other drives it has not shown much performance degradation.  There have been a few other bumps in the road during the tests, check out the full story here.

"Our SSD Endurance Experiment has reached the half-petabyte mark, so it's time for another checkup."

Here are some more Storage reviews from around the web:

Storage