Toys N Bricks and Brickset are reporting that Canadian Wal-Mart stores and UK Tescos are starting to get Series 4 Collectible Minifigures. This feels like the fastest rollout to date for several countries (thank you TLG!) The Canadian figures are listed for $3.28 CAN, while those in the UK are going for 1.97 GBP.
The two locations have been added to the Series 4 Rollout Map. Make certain to 'drop a pin' when you find these in your neck of the woods, or drop me a line and I can do it.
Keep checking back for more Series 4 news, as it happens.