Kansas is definitely lying to the Winchesters.

These are the things I thought I knew:

• The boys keep Ruby in a Devil's Trap for a while during season 3
• As a result of the crossroads deal, Dean gets dragged to hell by hell hounds at the end of season 3

And in reality:

• The boys trapped Ruby in a Devil's Trap for about 10 minutes worth of airtime (roughly a few hours of actual time, I guess) during "No Rest for the Wicked"
• As a result of the crossroads deal, Dean gets dragged to hell by hell hounds at the end of season 3. Not surprisingly, there doesn't seem to be any peace now that he's gone.
  

There are a couple of other things related to spoilers that have come up already, but the actual spoilers have yet to be confirmed so I won't list them. I'll just say that Lilith is around already and the Trickster is still around and for some reason was focused on preparing Sam for life without Dean.