So we'll be able to use the Trezor to essentially "store" both Bitcoin and Litecoin in the future?
Not in the future, that's something what's built into TREZOR since beginning. There just was no UI for Litecoin yet, but it changes with Electrum-LTC...
And yes, thanks to BIP32/BIP44, one seed can contain unlimited count of altcoins, so you can store all your cryptocurrencies on one TREZOR.