Recently I've been mining bitcoins as well as litecoins, namecoins, ixcoins & devcoins. I've traded some of the other types of coins for bitcoins, but was wondering if there is any consensus amongst the rest of the community if it makes sense to keep all these other coins in case they themselves become valuable someday. I've heard people say that as bitcoins become harder to mine, and more concentrated (and therefore less float) people may turn to litecoins as they are easier to mine and there will be more of them. This of course may or may not be true, we won't know for some time.

So... Do people trade their other coins for bitcoins or keep them just in case they increase in value?