Taylor seems to have replaced mahogany with "Urban Iron Bark" in some (or all) of their 500 series guitars:
Formerly the home of our mahogany models, the 500 Series now boasts back and sides of Urban Ironbark, an all-new tonewood sourced from our always-growing urban wood initiative.
While recycling of urban resources is a responsible and possibly profitable thing to practice, I really question scrapping a wood that's long been associated with quality guitars and Taylor's 500 series. I have no idea what kind of tone wood Urban Iron Bark will make, but wonder why could Andy Powers have not just created a new line of recycled wood products. Maybe even revisit the notion of guitars made from oak pallets....