I believe that sooner or later we will come to the conclusion that smart contracts will make such property transfer transactions possible.
Probably later. Smartcontracts cannot interact with any data from outside the blockchain.
The way blockchain is designed does not allow it to interact with outside data. You will need an Oracle for that, and there is no functional Oracle yet.
This is why all smartcontracts for now are icon related, or tokens exchanges (like Dex or whatever). And some few minigames like cryptokitties (cryptokitties are just a different kind of token, erc721)
A land transfer by smartcontract is not possible for now, because land property transaction is not registered in he blockchain