CJ,
Excellent point, and all should heed it. Not every guitar is made to withstand 13 gauge strings. And some 13 gauge strings have more tension than others.
I suspect that all Guild acoustics and starchtops withstand 13 gauge, but I suspect that a lot of Taylor guitars are going to turn into accordions.
Usually I use 9 stainless on my solidbodies, 10 stainless on the archies, and 11 phosphor on the flattops (but enough about Rosie). And when I'm not playing them, I de-tune the strings with the highest tension--3, 4, and 5. The last measure is opposed by many Guilders, however.