In other words: I launch a Macro app, press the "record" option, and then a little blue bar appears at the top of the screen (like when I'm making a phone call) and says "Touch here to finish recording macro". It then makes a history of whatever app(s) I'm touching and where on the screen I'm touching. I stop the macro, then set it to replay at certain times - hourly, daily, weekly, and so on.
It would be an enormously valuable piece of automation - imagine using it to take stop motion pictures, send email notifications, or play a certain song at certain times... it would reduce using apps to the level of repeatable, atomic actions and allow people to be even more productive. They would just need to tie it into the native timer used by iPhone OS.
There's no reason why Apple couldn't implement something like this by their next OS release.
(This post was motivated by a desire to replace my clock radio by using an alarm on the iPhone to launch the NPR app and listen to the live stream of WNYC)