This will vary from location to location depending upon size of the store and how fast the items have been selling.
I visited a dozen LA area stores in the last month to shop and also to put our local NAR club stickers on the rocket products (LAUNCH SITE INFO: xxxxx). One had a brand new gigantic display in the aisle at normal price. Biggest display I've ever seen. Most folks with kids were forced to stop by the kids as the wheeled by. Other stores had the Maxtrax and Snapshot for $19 on clearance in the normal shelf space. Others had nortmal displays and normal prices.
WHEN a product is finally dropped from the normally stocked status at all Wal-Marts, they will then either let them sell at normal price until gone or mark them down to move them out. Either way, they will get moved off the normal modular display area to make room for the new product. I love seeing the layout sheets taped to the modulars just before the new items show up.
BTW, Michaels will also do a seasonal dump at some locations and keep them year round at other locations.