To conclude, there's perhaps no more apt way to conclude this piece, than to quote this very fitting statement by contract law attorney, Ivan Hoffman, of California: "[Given that] the letter of intent is essentially a legally worthless document [but yet one that could potentially cause many serious legal problems for the signer]. It is not clear to me the reason any party would ever bother to create such a document and yet I have seen it used on many occasions."
Another recent decision of the Supreme Court addresses two key points. The first is the need to have agreed contract terms, before work starts under a contract and the second that, where a letter of intent is signed and work starts due to it, that a contract must be finalized as soon as possible after that. In this case, the parties entered into a contract formed by a letter of intent. When the letter of intent expired the work continued on, before the terms of the detailed written contract had been finalized.