Best Buy has a sale on now through Monday where you can get the 16GB model for $449 ($50 off) and the 32GB ($50 off) or 64 GB ($150 off) models for $549. There is also talk that Stapes will be offering 50% off the PlayBook on 7 and 8 September so you could get the 16GB for $249, 32GB for $299, and 64GB for $349. Keep in mind these Staples deals are just rumors still, but the Best Buy sale is going on now. I have a 32GB model that I paid $599.99 for so these are great deals.
I also noticed this past week that the Rapid Charger Dock was on sale for $34.99 (regularly $69.99) and picked one up for myself since I prefer charging my PlayBook up in this stand. The soft shell case is on sale too.
While these sales are great, they are not close-out fire sales and I think they are just holding these to move inventory and do not personally believe there is a new PlayBook coming anytime soon. The 7 inch form factor is great for the PlayBook and I hope RIM is just dedicating resources to the next update and not future larger form factor models.