My husband & I enter into a verbal agreement with my mother on August 10, 2007 that she would give me the land I was to inherit now so that my husband, who is a carpenter, could build me a house on that land.
We hired someone to do the blue prints and even made arrangement to live in a house and remodel it for two years in exchange for rent so we could save money for our house.
Yesterday I received a call from my mother telling me that she had already promised the land in front of my property to my daughter and her husband says that he will not allow her to put a house there if we build a house on our land, because he does not like my husband.
She says she will not turn her back on my daughter so basically she is going back on her original agreement leaving my husband and I in quite a predicament. We've already spent a lot of money and made a lot of plans.
Is there anything legally I can do. My mother is notorious for doing this sort of thing to me and it would not hurt me one bit to take her to court over it. She and my Stepfather are worth about 25 Million dollars.

Not completely sure but your question reffers to Real Estate Law or Other Law.
In my opinion you need of a lawyer.There are many details and I do not think you will have full answer here.

You might have a case to recover the costs incurred in planning. You will have to prove that you had thise agreement. However, she can change her mind so you can't force her to give you the property.

This question has to do with a verbal agreement and it's validity.

A verbal agreement can be binding if it can be proven.

It's in her will that I get the property, she just wants to keep us from building a house on it.

There were several witnesses to this agreement. We even had the electric company come out and give us and estimate on getting power to the property at her request.

Like I said, you may be able to recover the costs you incurred, but you can't force her give you the property or allow you to build on it. Since this was a gift she can change her mind.

Now, if she doesn't change her will and you inherit the property on her death and, if the will does not put any restrictions on the development of the property, you can build on it despite the daughter's wishes.