How weird - just browsing through behaviour&development topic and a two-year old thread was resurrected www.mumsnet.com/Talk/behaviour_development/592367-16-month-old-not-pointing-waving-or-talking-worried
Had posted on it myself (I used to be FattipuffsandThinnifers, and spent most of my time on MN on the b&d section in those days). I was so in denial about ds! Convinced myself his late pointing, being a bit in his own world, his obsession with spinning etc was all ok, he was just a boy etc etc. 
Feel bloody awful that I had those niggles even when he was 18 months old and still didn't do anything till he was nearly 3yo
Wonder if acting earlier would have made much difference - guess I'll never know.