I understand that redstone is going to be changing, but I'd like a confirmation if you intend to change it on this scale. I have a copy of "MCAs Redstone Circuit Gallery" (I lost the download link) and out of the 18 monostable circuits that function in 1.4.7 15 of them are broken in 13w04a.
I think I got an angle to get every component of each device. The wool to the right is simply color coding to keep track of which devices break in the snapshot. I only uploaded the devices that work in 1.4.7 and break on 13w04a.
I don't know any way to debug what the actual willingness numbers are, so I'm going based on what the Wiki says about how they behave. Feeding villagers was a 1.8 addition.
I have confirmed that I can trade with villagers and they will get hearts and breed. When I turn mob griefing back on I can throw potatoes and wheat at their feet and they pick them up. Turn mobGriefing off and I can throw all the food I like, they will never pick it up.