LiteCoin was actually designed to be hard to mine on the GPU, due to the memory requirements of the algorithm. Of course, people are smart and managed to figure this out. Eventually, somebody /might/ be able to come up with dedicated hardware to mine LTC, but it's likely to be much more expensive and difficult to produce than the BTC ASIC hardware, and the value of LTC is nothing like high enough to make that a profitable thing to be trying to do at this stage.