Why does an iPhone need a computer?

The iPhone is a bridge device that is moving away from the tethered computer model. It's about time. If you look at the latest version of the iPhone, you have several features that all rely on a data connection to work:

• Maps
• YouTube
• Stocks
• Weather
• iTunes Store
• App Store
• Email
• Safari
  

There are applications which require the GSM network:

• Phone
• Text
  

Then there are some features that can either rely on a data connection or use a tethered model:

• Contacts - Sync with Address Book, or sync over the air.
• Calendar - Sync with iCal, or sync over the air.
• Photos - You can email your photos or use iPhone to transfer them.
  

There are applications which do no syncing at all:

• Notes
• Clock
• Calculator
• Camera
  

Finally there is one application which requires a tethered computer to be useful:

• iPod
  

It makes you wonder why Apple has chosen such an inconsistent approach to their data model. Why can some data be synced over the air (OTA), some only over WiFi, and some requires a computer? I'm surprised that they haven't simplified this to at least WiFi and OTA.

The specific inconsistency that really bothers me though, is why do I have to download PodCasts on my computer before I can put them on my iPhone? Usually the Podcasts are the same size as a large audio file, and most are under 10MB (which is the limit for OTA App Store downloads), so what gives here?

I think Apple should take a look at their sync strategy, and figure out what the iPhone is supposed to be. Is it an accessory, implying that it should be tethered, or is it a stand alone computing device that happens to share music with your computer?