Although I bought my own HV20 my in laws gave us considerably more money than that to help towards our holiday this year so we could enjoy as a family, DisneyWorld, Universal and St Petes Beach in Florida. Without their help we would not have had the opportunity to go, and for three weeks.
You should say thank you and reward them with what they want, and that is images of your lovely child soon to enter this world, this will give them great pleasure.
Without sounding morbid in anyway they're giving you this gift so they can share in this family happiness now. What good will it do when things (hopefully a long time in the future) change.
It's a great camcorder so buy it, in all its' hd future proofness and buy your mum in law a nice floral arrangment.
Ps. I'm getting to grips with the Sony Vegas editing suite so I can render a decently produced DVD of our holiday, and I know that my mum and dad in law will be overjoyed in watching it. (when I get it finished).