After having a look at the mining calculators, it seems that the new scrypt miner from Bitmain is gold. The ROI looks to be 2-3 months, pumping out over $1000 USD after it has paid for itself.
There are some things to consider, such as the rapidly increasing difficulty. However, with a return like this and LTC holding steady at $45, profitability should be maintained for many months. If the price of LTC continues to climb, these returns could be even greater. From what I've seen, LTC appears to be resilient in the face of a pull back, and I have confidence that it will at least hold steady as others fall.