My husband and I are American with one child. Does anyone know, do we need a Swiss will and/or a US one? Our assets are mostly still in the States. Thanks.

You can either write a Will under US law or Swiss law but be careful of writing a Swiss Will because of forced inheritance rules:
More information/discussion here:

http://www.englishforum.ch/housing-g...king-will.html

Writing A Swiss Will

My understanding is that if you die in Switzerland your estate will be handled by Swiss law. This can be quite odd if you don't know it and may result in children and brothers and sisters being asked if they want some share of it.

However, if you have a will made outside Switzerland you can over-ride the Swiss law with a simple hand-written will - no need for a witness - stating that you wish your last will and testament to be according to US/British/whatever law and refer to your Your Swiss bank may be a good starting place for this...