Are we sure it
won't have an OS other than the iPhone OS?
Anyone who says they ARE sure of anything about this project (the device details, even just the existence of the device) is probably lying through their teeth

(that, or they're part of the project itself, but those people probably wont be commenting AT ALL)
I can tell what _I_ am sure of:
1) If it has an iPhone OS X, as opposed to just an iPhone UI, then I wont buy it. The ideal would something like a new UI mode on top of desktop Mac OS X, such that you can do everything the full Mac OS X can do, but with a finger interface. But it would be acceptable if it's a 3rd OS X, somewhere in between iPhone and Mac (the distinction being that it might not be able to run desktop apps themselves, either due to extensive UI changes, or CPU architecture).
2) If it doesn't have an open application interface (ie. I can download some apps from the general internet without having to go through a store), I wont by it. A store would be nice (for both this device, and for the desktop Mac OS X for that matter), but being able to download apps without going through a store is _mandatory_.
3) If it doesn't have USB Host/OTG ports for input devices (at least a keyboard, mouse would be optional), then I wont buy it. It would be nice if it also had a display output port, the combination of which would allow me to effectively use/treat this like a standalone computer.
4) I can understand if it doesn't let me externally access my music data ... but all of the rest of the data (my notes, documents, etc.) must all be exportable/syncable/accesible, or I wont buy it. Preferably accessible via mounting it on my desktop device in a storage mode (like the way you used to be able to do with classic iPods), and/or having this accessible user data be stored on a removable SDHC card (so, applications and iTunes data on internal, non-accessible, storage -- and an SDHC card slot that gets exported to the desktop when you connect for syncing, that stores all of your user created data, and can be user upgraded/etc.).
(it would also be nice if the USB ports from #3 could work with #4 to allow for connections of external storage devices, like SD card readers, USB hard drives, etc.)