A recent TrendMicro press release confirms that Asus will indeed eventually port their DPI engine to the RT-AC56 and RT-AC68:
http://apac.trendmicro.com/apac/about-us/newsroom/releases/articles/20140827151514.html
New TrendMicro DPI engine announced for other models
http://apac.trendmicro.com/apac/about-us/newsroom/releases/articles/20140827151514.html