I've finally persuaded wetsuit to take a serious look at LN. It came from a discussion we had recently about our dust problem (229 BTC that's too expensive to consolidate).
I'll gladly open a Lightning Network channel to freebitco.in once the option becomes available. As to sweeping the dust, can't just you just sprinkle a small amount via every withdrawl? It might take a little while unless you wait for an opportunity when fees are low and you can sweep some/most dust in a series of transactions.
It is just a question of how much of the value we are prepared to pay to move it. If it costs more than 0.5% of the value then we leave it where it is. Because we consolidate 50 deposits at a time and apply that 0.5% limit to the total value that means bigger deposits to pay to sweep smaller ones. My plan is that after LN is active we can deduct 400 Sats from new dust deposits and that will pay to consolidate itself + one old dust deposit.