Adam, thanks for the informed insight, I get what you are saying but I just have a different take on the whole "street date" thing. I think it helps a lot to make new releases an "event" based on firm dates because it allows you to build a targeted marketing and production push at a national level. If Hasbro had any control over when their product hits the shelves, it would really enhance their ability to accurately forecast sales projections over the course of the year, so they can refine the release dates over time and optimize their strategy.
Hasbro certainly thinks it has the ability to control their product, as most of their new male action lines do have specific launch dates for the first wave(s) when a big push happens. (These include: Episode I, Saga/Attack of the Clones, Revenge of the Sith, Transformers [Movie], Transformers [Animated], Indiana Jones, The Clone Wars, Wolverine/Marvel Universe, Transformers: Revenge of the Fallen, G.I. Joe: Rise of Cobra. These all had street dates on the boxes for some or all of its early waves of product.) As you probably noticed, Hasbro does have a strategy as to when new products and waves hit. And these targets (more ranges than specific dates) are sometimes missed, in particular, you can see this in Q4 of 2007 and 2009 Hasbro Star Wars lines. Things just happened to get pushed back for various reasons, some of which I am not at liberty to discuss.
For marketing purposes with lots of items, it definitely has a (potential) place. For some reason, retailers are usually able to coordinate things with Star Wars nicely on those big launch dates. (The big ones, anyway. There were sometimes secondary dates for like a month after the main launch and these tend to be totally ignored.) A big launch gets free press attention (local news), fans go out with friends who may not be collectors who want to see the spectacle, and stores get big sales.
If you've watched this stuff closely the stores basically ignore it for everything that isn't Star Wars, Wal-Mart in particular. The 3 3/4-inch Marvel Universe line and Wolverine were supposed to have a strict street date, which Wal-Mart ignored at many locations and put everything out early. With Transformers, some items got put out early for the first movie and a lot of stores put stuff out a little late for the second one, thus missing the entire point of a large launch date. And with Transformers: Animated, there was an advance release in (if memory serves) Ohio while the rest of the country was supposed to wait to put them out until a specified date-- who benefits from this? Some Wal-Marts, again, ignored this and put them all out, which is why I got my Animated stuff at Wal-Mart. A lot of the stores I frequent missed the Rise of Cobra date and just put the stuff out whenever, typically late.
The thing that really gets my goat is restrictions-- when an item scans as "do not sell." Usually because the store is uninformed and thinks the item has been recalled, which it rarely (never) is. As a collector, I know the score, but what about the kid who finally convinces mom and dad to buy a figure, they take it to the register, and the kid's out of luck? That sucks. Just sell the damn toy.
I agree with Jayson that with exclusives, it does seem sensible. When it works, of course, assuming the store remembers to put it out and/or it doesn't get siphoned off before the street date.