Depends on how you do it. There are lots of ways to transfer assets down to the next generation to avoid tax. I won't list them all here, but the key point is that most of them take time to implement and the important part is to plan ahead and not wait until you're nearing the end of your life.
Gift tax is similar (has been 45%, might go up), on amounts over $10,000.
It's now $13,000 as of last year, I believe.
Charitable giving is exempt, though...
And if it's a married couple, that's per person, not per estate.