I hate the uMBP trackpad. Here's why- assume for a minute that the touchpad doesn't have a physical click when you press it (like the iphone), so the only way to click or drag is to tap. That means you have to have to use tap-to-drag. The problem with tap-to-drag is that it adds a slight delay to tap-to-click; it is short but noticeable if you compare it to tap-to-drag disabled or the physical button. Tap-to-drag also has a delay when you want to release, in case you need to move your finger or you take your finger off slightly, which becomes a problem if you actually want to release what you are dragging (the first problem the OP described).
Obviously, it sounds like it is best to just disable tap-to-drag. The problem is, dragging with the physical button is frustrating. Trying to do it with 1 finger is hard because of the amount of pressure it takes to keep the button from releasing (I think there is an adjustment, but it is too stiff by default and not really user-adjustable). Also, the button doesn't really click near the top. Trying to use two fingers (the way you would if the touchpad had a real button) doesn't work well either because sometimes it forgets you are dragging and thinks you want to start scrolling or something.
Having a little patience shouldn't be necessary. What if you have to drag-and-drop a large number of objects individually? Why should you have to wait after each one when we have the technology to do drag-and-drop with no release delay? Why should every tap be delayed slightly for click-to-drag (assuming there is no software fix) when a physical button for dragging and tap-to-click works better? It's frustrating, and if Apple keeps making dumb design changes (no expresscard, glassy screen (ok, they fixed that one), no eSATA, no button touchpad), I would not buy a new MBP as my primary computer.
/rant
