It would seem, in the grand scheme of things, that a To-Do list would be an easy addition, with it’s value greatly eclipsing the necessary investment. All the people I know who are on the fence about buying an iPhone are doing so because of:
a) a lack of sync-able notes (which is being taken care of)
b) no syncing with to-do lists
Now, if Remember the Milk was featured as a supported to-do system, that’d be the cat’s pajamas.