Google's long-awaited Android 4.4.3 KitKat update has begun rolling out for the Nexus 5 and Nexus 7 as scheduled, following two recent announcements made by T-Mobile.

So far, the Google Nexus 5 and Nexus 7 have been the only devices confirmed to be receiving the Android 4.4.3 KitKat update, and for T-Mobile subscribers only.

T-Mobile announced Monday on its support page that its Nexus 5 will be upgraded to "Build version KTU84M", and the Nexus 7  to "Build version KTU84L". This information has recently been confirmed on Google's server as well.

The nationwide mobile service provider will be the first in the United States to be rolling out the Android 4.4.3 KitKat update, beating out its competitor Sprint. What makes this development unusual is that Sprint usually rolls out the latest Android updates first.

Back in April, an incident occurred over at Sprint when it mistyped an announcement -- leading users to believe that the Android 4.4.3 KitKat had been released with the Google Nexus 5. The typo was quickly corrected.

There is still no confirmation as to when the new Android 4.4 KitKat update will be available for other mobile devices let alone other service providers. Even so, there exists the possibility that the Android 4.4.3 KitKat Update will be rolling out across the board in the coming months.

According to DroidLife, the Android 4.4.3 KitKat Update comes with an all new dialer - a screenshot of which were accidentally leaked by Google Nexus' own Twitter account in April. Changes were relatively minor, says the report, with emphasis being placed on color and aesthetics.

T-Mobile's release of the new Android upgrade trumps earlier speculation that Google will not be rolling out the Android 4.4.3 KitKat Update for any of its Nexus series devices.

Possible Android 4.4.3 KitKat rollout for Samsung's Smartphones and Tablet

Rumors in the past weeks have also suggested that Samsung's Galaxy s4 and Galaxy s5 smartphones will be getting the Android 4.4.3 KitKat update, along with the Galaxy Note 2 and Note 3 tablet.

Last month, SamMobile leaked an allegedly authentic internal memo that named the Galaxy s4, s5, Note 2 LTE, and Note 3 Neo within a list of devices getting the Android 4.4.3 update. The estimated launch dates given in the memos were between May and June of this year.

As of now, none of Samsung's tablets and smartphones have received the Android 4.4.3 update, even though that may change in the following weeks in light of the recent rollout over at T-Mobile.

The new Android 4.4.3 KitKat update is mainly a bug-fix, and will not bring any significant changes to the existing software. It is still good to upgrade to the latest Android update if and whenever possible, however.

The Android 4.4.3 KitKat update is the last of the Android 4.4 KitKat upgrades, and Google may be developing the Android 4.5. Though there is much speculation, no nickname officially exists for the fabled Android 4.5. Even so, Google does have a history of naming its Android updates after sweets and confections, so it is likely that the tech giant will be following in this same tradition with the Android 4.5 as well.