The Tech Report have hit the 200TB mark on their testing of ~250GB SSDs from Corsair, Intel, Samsung and Kingston and the drives are starting to feel it.  At the 100TB mark Intel and Samsung drives started to lose blocks of storage and at 200TB all but two drives have shown evidence of degradation.  The non-Pro Samsung 840 has suffered the most but its performance is very similar to what it was in the beginning while the Corsair and the Kingston drive receiving only compressed data report themselves in perfect health.  Check out the exact performance deltas in their article.

"We're in the process of hammering six SSDs with an unrelenting torrent of writes to see what happens as the flash wears out. Today, we check in on the drives after 200TB of writes."

Here are some more Storage reviews from around the web:

Storage