Microstock mergers & acquisitions

Can we say that holiday shopping season just got started? I think it actually started when parent of #2 (IStockPhoto) snapped parent of #5 (StockXpert). Now #1 (Shutterstock) takes #6 (BigStockPhoto). What should #3 (Dreamstime) and #4 (Fotolia) do, merge? This way Big 6 will be reduced to Big 3 and rest of small players sooner or later will bite the dust. Wait, there is still the "biggest looser" of microstock industry Corbis they can drop big money on something change the balance of forces.