Besides, a lot of people have first to buy Bitcoins, then convert them to LTC and buy with them SXC. So if SXC/BTC market will be opened, I'm sure Vern will be happy with the trading volume achieved.
On the contrary. Cryptsy would actually stand to lose by opening SXC/BTC. Right now they are collecting percentages on two trades instead of one. First they take a percent on BTC/LTC, then they take a percent again on LTC/SXC. They have this luxury as long as they are the only game in town. Once SXC gets picked up on more exchanges, they will start to lose their SXC trading volume. THEN they might consider adding it to the BTC market, as a way to get the volume back.