>Furthermore, the wear-leveling strategies used in flash mass storage devices negates any attempt to securely wipe them short of physical destruction.
Well, it confounds it at any rate. But completely filling the device's memory 33 times in a row is pretty likely to overwrite everything at least once or twice - even the hidden "failure reserve" space if it's included in the wear leveling (and if it's not, then it doesn't yet hold any sensitive data, so there's no problem). Guttmann's values may be irrelevant to today's storage media, but that many repeated rewrites of anything still mostly does the job.
I don't know that I'd trust it to wipe vital military secrets, but it should do a good enough job for most anything in the civilian realm.