Practically, any LTC, TRC, NMC, FTC, etc. earnings could either be used to cover costs or be converted to BTC at market rates at
BTC-e, and soon MtGox for LTC, for dividends. Really seems like a pretty simple decision depending on what the cost of implementation and maintenance would be.
To me, Bitcoins are like paper bills and Litecoins are the cents. I'm more willing to gamble with Litecoins because I know they don't hold nearly the same value as Bitcoin.
That said, what would happen if Litecoin
was added to SD? EV would have thousands of Litecoins [profit] by the end of the month...and although that sounds nice, it's not if he only wants Bitcoin in the end. Converting mass quantities of LTC or any of the smaller alt-coins could pose two problems: A) People could bid up the exchange rate when they suspect EV is trying to convert to BTC, which cuts in on the final profit obviously, or B) constantly converting thousands of coins at once to BTC would kill the alt-coins value.
Either way, it's a pain in the ass. It's much easier, and vastly more financially stable, to stick with one coin. Obviously if EV intended to hold and spend LTC as we do with BTC, then this may be different...but as far as I can tell
most people use LTC as a means to convert to BTC.