heh, thanks all, seems I might have company on my desert island!
Those of you who are getting pestered to get married, I would advise sticking to your guns but check out where you stand in relation to wills, inheritance, power of attorney, health care directives, guardianship / custody (I don't think that's the right terminology but it eludes me) of the kid, any splits of money and property etc, the latter being key if you're planning to stay at home / off work for any long periods.
It sounds a bit gloomy as you'd probably only need most of this in the case of death or splitting up, but co-habiting couples often still don't have a lot of rights over blood relations when it comes to the crunch, and in the case of a relationship breakdown, women (it's usually women based on who is more likely to be the SAHP in terms of loss of income) can often find they have no easy recourse to their partner's funds if not married
if you address some of this you can wave it in the outlaws face 