Gone With The Whinge: That's right. The original article was in an ABM magazine but I can't remember the Dr who wrote it...bah. Either way, if you don't use a dummy, no need to start purely for SIDs prevention.
I just had a quick scan through the BMJ article that discussed the study http://www.bmj.com/cgi/reprint/332/7532/18.pdf and there's nothing that I could see (I was just scanning) about introducing a dummy if you don't already use one. The BMJ is obviously a report though, not the study itself. It did say that there wasn't enough evidence to make a causal link, but it did appear to be well worth further investigation.
I think it's fair to say though, that other factors make a far greater statistical impact - e.g. a smoking mother who puts her 2-3 month old baby to bed on their front. What's interesting in the BMJ study is a suggestion (not statistically significant, but still interesting) that the use of dummies might mitigate other environmental factors. So (and I'm simplifying here, not having read the full study) it may be that if you smoke and your baby sleeps on it's stomach, then a dummy will reduce their risk. But if you don't smoke and baby is on their back, a dummy will make no difference. Or will make a difference far more slight than the likes of Avent would focus on!
I hope there's more research though.