OoOh, a topic about shoes. My favorite.
If your trails aren't particularly gnarly, or are pretty hard packed, you're perfectly fine with a road shoe.
As trail shoes get more trail-y, they're going to slowly depart from road shoe feel and become more a trail shoe. That potentially means a) heavier, b) firmer, and c) stiffer.
If you want a trail shoe that is not extremely aggressive or a bit softer underfoot, I would recommend the Salomon Crossmax or Saucony Xodus, or a slightly lighter choice could be the inov-8 terrafly. Most mainstream shoe companies (e.g. Nike, Asics), also make quasi-trail shoes that are cushy and not aggressive, but are generally just road shoes with dark colours. If you want cush like nobody's business, try a Hoka Mafate.
If you want a lighter weight shoe, you're going to sacrifice a little bit of durability and cushion, but will often gain in flexibility. For that you could try the inov-8 X-Talon 212, La Sportiva Xcountry, Montrail Rogue Racer, New Balance 101, or the Saucony Peregrine.
Also, in full bias mode here, try on all the inov-8s. They're the best. Full stop. In the NZ they're distributed by High Beam,
http://www.highbeam.co.nz/
I'm getting the shakes. All this new shoe talk is giving me a hankering for some.