Please don't compare a platform with virtually limitless resources (PC) to a platform with constrained resources (Phone)

Architecturally they are designed differently, with full Windows they can abstract the interfaces to the hardware because they have the resources to do so.

On the phone they have to weigh how to do such abstraction because every additional instruction is extra battery power consumed, so less abstraction means more specific code to be written for each hardware platform.
Unfortunately that is how we think over here on this side of the ocean. You see, over here we buy the phone raw. Our phones aren't telco branded, locked, etc. etc. That's why we are used to buying expensive phones and changing them whenever we want.

The US model is different, the phone companies dont sell the phones directly to the user. The companies sell the phone to the telco, the telco decides what to put on the phone (apps, images) what features that gets taken in or removed (ie. remove any built in VOIP features, disable features when not on WiFi) this is Telco customization.

Whenever an update is delivered for the OS, the OEM will first test it to make sure it works on their hardware then the telcos have to test and ensure that it can work with all it's apps, and they need to disable all the features, bla bla bla. And that whatever new features introduced by the OS doesn't screw with their network.

The more customization a telco does to the phone the more time and $$$ it takes for the telco to get a new version out, hence the issue with the Android phones.

Apple doesn't allow much telco customization on the iphones therefore not much difference between telco updates.

Windows Phone 7 is a half half deal, the telcos can still customize certain parts of the OS but it's usually non essential (hence some phone's where the search button goes to Yahoo) But telcos would still want to go through the motions to ensure their network and phones dont get screwed when an update comes around.

MS on their part has released the table of telco's update schedule.
http://www.microsoft.com/windowsphone/en-u...dule-world.aspx
And users have already started screaming at Aussie telco Telstra since they havent even delivered first update.

The summary of this is that, the Telco holds quite a lot of power in the US to determine what phones get sold over there (look what happened to Nokia when they don't want to concede to the US telcos demands), and MS is actually trying to play nice with them by allowing some customization ala Android, but still dictate that updates need to be delivered in a given time frame ala Apple.

So they're stuck in an interesting position. My advice would be that if you want to get your WP7 updates as soon as possible, get an open carrier phone. Which is surprisingly easy in our country, technically our open carrier phones is worth alot to enthusiast since they will be first in line to get the updates the moment the hardware manufacturer finishes testing.

But my phone is Singtel branded