I am in law school and I've done stuff with family law. But, right now, I would not get a prenuptial agreement because I have no assets to protect...when you enter into marriage, everything you own prior to marrying, or inherit/gifted is your separate property. In a divorce, separate property should be traced to verify it as such. Hence, I'm not concerned about any inheritance I receive from my family being jeopardized in a divorce without a prenupt.
Premarital agreements aren't enforceable on any child custody stuff either.
Community property is everything accrued during marriage, including property, wages, and income from any separate property.
Most people probably don't even need a prenuptial agreement unless they have significant assets and if entered into, periodic post-marriage partition of property should occur annually or bi-annually after the marriage so the prenupt can be truly effective - it gets messy if commingling of assets occurs.
But as I said, for me, I don't see any point of having a prenupt unless I met and married Mr. Big Bucks and he wanted me to sign (and I would if requested).