Recently the block is full of spamming transactions (
http://www.cointape.com/). This situation have been for a while . I thought it was a test, actually not. If you don't include more than minimum tx fees, you have to wait long to get your tx confirmed. At the moment we have no implementation of large blocks yet, so we have to pay extra tx fees to miners.
what if i told you it was mining pools doing the spamming.. filling up blocks to force people to pay them more...
At first people were saying it's good to include 0.0001 BTC with every transaction you send. Nowadays I see that the average transaction fee is rising and that people tend to add a fee higher than 0.0001 BTC because they want to see their transaction get confirmed. Pools are somewhat extorting the users in a soft way to get more fees. When will they get satisfied? When people pay 0.001 BTC?
In the end, the problem will sort itself out..
Once the blocks are full for a longer time, and the queues just keep on expanding, people will be forced to add higher and higher fees to get their blocks confirmed. In the end it won't be profitable to send small amounts of BTC using the blockchain, so the volume of microtransactions will drop, making the queues shorter and lowering the fees...
It'll always end in an equilibrium.
Like the OP said, the microtransactions will probably move to LTC, DOGE, DASH,... since their blocks won't be full, so their fees will be much lower.