Yes, these stores always have sales, but they are not the kind of "door-buster" sales you see from stores like Sears or Wal-mart. I wouldn't expect Nordstroms to have any type of sale -- and if they do, it isn't going to be on a Kate Spade purse or Burberry colonge. Anything at Banana may be marked down slightly, but not significantly. I wouldn't count on anything significant at J-Crew either. Gap, Limited, Express, Ann Taylor Loft, Macy's and Filenes usually have sales.
What your going to find is sales on specific items. Like a sweater for $24.99 instead of $59.99.
I'm a Banana / J-Crew shopper too, so I agree, it sucks that they dont have "door buster" sales.