Is it just me, or do people here seem to overestimate the capabilities of modern technology, satellites, submarines and vastly underestimate the size of the Indian Ocean?
Even if MH370 left 10000 pieces of floating debris in a 5kmsq area, it is not surprising in the least that nothing been found yet. The search area has only been narrowed to an area the size of Texas, in a region which gets the some of the worst weather on the planet. With no landmasses to check the waves the swell is huge. Satellites can only pick out large contrasting pieces, and radar has difficulty seeing anything that doesn't break the surface, especially in large ocean swell.
And suggestions that submarines should just listen at random for the pinger are hopeless. The pings will only travel 2km and with a 500,000sqkm search area (at best) it would take years to search it all. In any case submarines tend not to hang around in this region of the world, because there is nothing there. Any submarines on there way will take some time to arrive.
It's remarkable we know as much as we do, but it's still not enough. Perhaps if we get a break in the weather and something is found soon, then maybe there is a chance to work backwards to the impact site. As the RAAF guy said, maybe then we will know which haystack to search.