Apple Watch won't be sold to walk-in customers right away, but you can book an appointment to try one
Strategic marketing aside, Apple's decision might boil down to its supply constraints. Display supplier LG seems to have yield problems, coming up with 60 to 70% deficit in plastic OLED panel production. Although LG has been making these for the LG G Watch R in a breeze, the panel on the Apple Watch is of higher resolution and has to be able to show 60 frame per second animations, which probably makes it harder to produce. Additionally, Quanta, which is Apple's main manufacturing partner for the wearable, is struggling with yields too. By the end of March, only 300,000 units a month were shipping, which is a far cry from the 1.25 to 1.5 million units Apple wants to output on a monthly basis. Initially, Cupertino aimed for 2.5 million to 3 million, but this proved too ambitious a target. Now, rumors are talking of a 3 million Apple Watch initial supply, so be prepared for some waiting around.
As with all things Apple, the production hurdles will probably be cleared in a quarter following the launch. You may remember that the Apple iPhone 6 Plus was a bit hard to come by in the beginning, due to issues with the touch panel and coloring among other things (such as balancing the supply and demand ratio). But things were largely okay in a few months after the September reveal. Regarding the Apple Watch, it is rumored that longtime partner Foxconn could be brought on board to help with the Apple Watch assembly, which would definitely lend a helping hand.