Do MacBook Air's SSDs fail? I have seen many discussions describing SSD as fail-prone. I have read Jeff Atwood's warnings. Portman Wills' experiment looks alarming:


Super Talent 32 GB SSD, failed after 137 days 
OCZ Vertex 1 250 GB SSD, failed after 512 days 
G.Skill 64 GB SSD, failed after 251 days 
G.Skill 64 GB SSD, failed after 276 days 
Crucial 64 GB SSD, failed after 350 days 
OCZ Agility 60 GB SSD, failed after 72 days 
Intel X25-M 80 GB SSD, failed after 15 days 
Intel X25-M 80 GB SSD, failed after 206 days


Further research yields that a rule of thumb makes an SSD cell with more than 100,000 writes practically unusable.

While not being specific, Wikipedia warns against Flash SSDs. DROM SSDs, on the other hand, are safe, according to them.

What type of SSD are MacBook Airs built upon? Are they fail-safe? What is the typical lifespan one can expect?
MacBook Airs ship with either Toshiba or Samsung MLC SSD drives.

No SSD drives are fail-safe.

Lifespan of an SSD drive depends on what wear levelling techniques are employed by the manufacturer and the operating system and what exactly a user does with his/her computer. There is no reliable figure.

My own view with SSDs (as it has been with hard drives) is prepare for the worst and backup regularly. Take advantage of the manufacturer's warranty should a drive fail.