Siri should be a small panel, say 300 pixels high and full width that pops up anchored to the bottom of the screen, and gives feedback (text output, results, spinning circle when processing). The app that was running when Siri was summoned resizes upwards, the same way iOS resizes downwards in the event of the double height status bar. The user is this way free to simulataneously interact with the current task while they interact with Siri; as an added bonus the painful wait every time network conditions aren't perfect will be much less annoying and noticeable. And to close just swipe down on the screen and it drags the whole thing down and out of view. Seamless. Discuss.