MAST = Merkelized Abstract Syntax Trees

1. You will now be able to write and execute detailed smart contracts on the BTC/LTC blockchain.
2. BTC/LTC will be faster, avoids further scalability issues, and brings increased privacy to its users.
3. Furthermore, increased privacy will facilitate anonymity for settled transactions. For example, right now LN transactions are easily identifiable because of the P2SH hash they use. In light of this, nodes are capable of censoring LN transactions should they choose to. MAST would be able to hide LN transactions by making them indistinguishable from other blockchain transactions.

This will be implemented on LTC quite a bit sooner then most people expect, and BTC will follow suit but it will likely take far longer for BTC to adopt this new release.

If you look into what LTC has planned, I feel it will soon be seen as the most universal crypto in the entire space, offering all the major benefits of some of the largest cryptos out there (smart contracts that rival ethereum, privacy that rivals monero, speed that rivals dash and so on... interesting times ahead for Litecoin!)