As long as they keep the price low, even $200 or so like the forty shorty, this could be good to have in the lineup. Don't get rid of the current 50 1.8! It's such a great price for people just getting started to get a fairly fast prime at a good focal length.If this is considered a replacement for the 50mm f/1.4 (as the post states), you won't see the retail price cheaper than $399. More likely it'll be $500+. If this is a replacement for the 50mm f/1.8, then you might get lucky and see $249 or $299. But, then why would anyone buy the 40mm pancake, when you could gain f/1.8 and IS for $50?
So yeah, I'd say $399 is the low price, more likely to see $599.