Right now the biggest things going on for BTC are basically:
1) Being the original altcoin: Has higher status than the rest of alts
2) Has a better and faster transaction time.
Unfortunately for LTC, BTC is going to increase its blocksize limit in the next update, which means Bitcoin will be faster than ever, therefore is one less thing that makes LTC worth it above BTC. Right now if i was holding LTC; I would keep holding it until the next pump (if it happens) because it truly cannot get any worse.
The proposed hardfork for blocksize limit has no effect on transaction speed or confirmation time(except indirectly if too many blocks are filled). Bitcoin will still have a confirmation averaging 10 minutes and litecoin 2.5. It is features like the "lightning network" which may bring instant confirmations in a decentralized manner-- currently we only see instant confirmations with btc payment processors.