Biggest miner on MPH was 200 Kh yesterday, now there is one at 1,400 and another at 400. I'm guessing either the botnets are getting back in the game or someone figured out how to get their asics going on this version already.
Or GPU mining farms joined back. Yesterday blocks were too slow to mine.
That top miner at 1400 Kh would be something like 1500-2500 high-end GPU's. A bit hard to believe for a single farm. Not to mention if you had a farm that big, why not solo mine? It's 13% of the entire pool. If I was a gambler I would bet on a botnet. But seriously hoping it isn't asics. I don't really know enough about the v7 changes to make any sort of intelligent comment about the feasibility of modifying the existing asics to work on the new version.
You're definitely right though about profitability being no good yesterday whereas right now it's looking pretty good.