Pending never good for the party already signed. In fact, many contracts only have/need one signature such as vehicle purchase contracts, cell phone service contracts, merchant sales contracts... All these contracts with one signature can be enforced by the other party never signed. So "one signature contract doesn't bind you into contract" is not true.
In rental arguement with the contract requires two signatures sometimes not even reqires signature from any party. If the landlord sent the tenant an unsigned lease contract and ask the tenant to sign and the tenant never signed it, and now the tanant wants to stay when the landlord attempt to evict the tenant. In the cour, the landlord most likely will try to prove the contract is not enforceable since no one has signed it. However, the tenant will argue your "intention" by the time you sent him the lease contract. If you didn't appove the lease, why you sent him the lease? So the tenant effectively proves landlord's original "intention" is approved and agreed. The landlord could argure he changed mind now. Well, the person who changed mind is going to responsible for the bad thing in most case. When the case has no black and white to make the decision, the judge is going to rule the case by the "intention" of the parties and most of the time the judge lean to the tenant side.
