A note on the difficulty:

What it seems to me is that the S4's are on the market and people everywhere are dumping their old miners. I came across a post from 1l1l11ll1l last night (https://bitcointalk.org/index.php?topic=813649.msg9110299#msg9110299).. As people dump their old miners for the new ones, or just dump old ones for power issues - there is a significant amount of power leaving the pools.

Granted some of it is being replaced but I'd argue that a lot of it isn't.. Combine that with people who used to mine Bitcoin but have decided to switch to scrypt and I'd say that these two factors are what has been driving the difficulty down.. As more people pick up the old S2's and S1's the difficulty will increase again but it might take a couple of weeks.

I myself just picked up a S2 for $350 on ebay and in doing so I've taken about 243 gh/s offline. And the person that sold it to me took about 1000 gh/s offline.. It's the ripple effect of new miners taking over - it will go back up but right now all the miners are playing musical chairs with their hashing power.

yes.

1. People are trying to sell S2's on ebay for $700+, when you can get them for about $300 - $400. So there are a lot of units just sitting around because no one will buy them for that much money... A lot of them I'd say - All the major mining shops still have them listed for $800 or comparable. (http://www.amazon.com/Bitmain-AntMiner-1000-SHA-256-Miner/dp/B00KH9339O)

2. Some people went ahead and sold their old units and the new ones aren't in yet.. Totally feasible scenario.

3. I took my miners offline and they are just sitting at my office. I would run them but I don't want my landlord to start charging me for power so I try to fly under the radar (I'm really pushing it at 1050w though!! lol).

4. It's just a theory.. It's probably half true and there is another factor I've haven't thought of.