This is a "feature" I actively avoid. Why in the world would anyone want to buy something online without a chance to review their purchase? Other web pages don't even let you leave the page without asking "are you sure?".
it's been a while since i've bought from amazon, but i recall that one-click orders have a delay before being 'executed'. this lets you use one-click multiple times and have items bundled to save shipping, as well as review and cancel.