I think most people missed the boat on LTC. The smart investors realized that LTC would grow, because currencies that are new can have the most gains in the shortest amount of time, so they bought in early (not to mention that LTC is marketed as BTC's silver). Just look at BTC. A 5000% growth in one year time. BTC will never achieve that performance again in the coming years. Perhaps a 20x growth, but the growth in percentages will keep going down over time.

Because of this enormous growth in the early stages, people will be incentivized to buy coins that are still in the cents or 1 dollar range. Those coins have the possibility of achieving growth gains that are in the thousands of percentages. But right now, LTC is 20 dollars. I think its max market cap will be 500 dollars, because it doesn't give any real advantages over BTC and will thus remain a speculative instrument mostly. Those growth gains can be easily achievable with BTC, since I'm positive that we are in between the innovator phase and the early adopter phase.

It might still be worth a shot, because there are rumors that Mt. Gox will implement LTC, which will greatly increase its legitimacy. But it's up to merchants to adopt LTC besides BTC. As long as they don't do that, LTC's market cap will be limited and it's growth will only depend on speculative interest.

Right now, it might be worth looking for the next candidate after LTC, the one that has the best chance after LTC and that's still in the cents stage. If it can be ascertained for sure which is the best third coin, it would almost be a given that growth percentages of above 1000% and more will be achievable due to sheer speculative greed.