Don't quite agree that it's a fad.
Suits with patch pockets have been around for a looooong time (check out voxsartoria's blog for its excellent pictorial history, which shows quite clearly how classic style never really changes).
That said, they are casual suits and may be inappropriate in some of the more anal-retentive organisations (UBS for instance) where senior managers notice such details.
I have one suit with 3 patch pockets and wear it on Fridays and Sundays (for Church) with Shantung and knit ties. Of course, my company's philosophy is simply this: if you wear a suit, you're dressed up... and WTF are patch pockets?
I would not pull the trigger unless you already have navy and grey staples (welted breast pocket; flapped and welted hip pockets).