None of late from this niche community will overtake bitcoin, however something commercial may in the longterm. Most the flavors of the week here will die.
I also think (and maybe called crazy here for doing so) longterm ltc could surpass btc (just from an investors on the street point of view due to fairness, well percieved fairness).
LTC fails on it's original goal of being ASIC resistant. I'm sure that would deter investors from further putting their money in the coin, as it's value would only go down over time...look at the charts, it's already went down over 30%.
Most of those old coins are not doing so well, Peercoin, Primecoin, Litecoin, there prices are only getting lower as people lose interest and move away from them.
It's the new coins like Darkcoin, that would end up taking the lead and the spot right next to Bitcoin.
You're talking from the point of view of this little niche crowd, both BTC and LTC are heading wallstreet investors. They don't care about mining whatsoever. BTC will have a ETF in a year + then there is a followup LTC one. thats when the scene will really heat up.
BTW LTC was never designed to be ASIC resistant, ASIC was a non issue at the time of LTC creation.