I've got a 16" Giant Trance 3. It weighs 13.5kg (29.76lb) and that's with a oversize hussefelt bar & stem (heavier than stock easton ea30) and Panaracer Fire XC typres (heavier than the stock bulldogs).
I reckon that's pretty darn good as my entry level hardtail weighed about the same (but it was half the price of the Trance - it was a Specialized Hardrock Comp 01 model 17").
My husbands Specialized Hardrock Comp 19" weighs 13.5kg (29.76lb) but it has an alloy rack for a baby seat on it at the moment.

So to complicate things obviously it also depends on the frame size - that will affect the weight of the bike. I know I could lighten the Trance up by getting differen wheelset and other bits and peices, but for me it's not worth the expense, it only would be if I was into serious racing which I'm not.

Hardtails at the same price point will weigh less because they generally come with better components (fork & wheelset). Some brands frames are heavier than others also (The Trance & Reign are said to be on the heavy side frame wise).

It's easy to drop 1 - 2lb in weight simply by buying a better fork. Next biggest place to save is generally tyres & wheels, stem, bar, seatpost and I think after that it's fiddly & expensive. Mind you the fork & wheels are the two most expensive components to save weight on so usually people will change the stem, bar etc first.

From what I understand I reckon around 30lb for a dually is respectable, 28lb is considered very much on the light side, and 33lb is getting towards the heavy side. I don't think I'd want my Trance to weigh much more than 14kg (31lb). I think my old Wallmart type bike used to weigh around 41lb!

For a longer travel duallie (more than 4's) I would expect weight of 31lb plus - probably more around 33lb.

But hey I'm definitely no weight weenie. Well not yet anyway.