Next generation Android OS is coming very soon and users should be aware which devices may get the first-hand major firmware update of the year. Here are some models with highest chances based on release dates and software support window period.

HTC Smartphones

HTC users will depend on the approach of the company regarding firmware updates. Some models have faced issues with drivers and software support such as HTC One X and One X+ which are both removed from Android KitKat upgrade plan.

- HTC One M7 and M8

- HTC One Max and Mini

- HTC Butterfly and Butterfly S

All of these devices are included in the Android KitKat plan from HTC according to @LlabTooFeR and still inside the 18-month software support window period. However, the Sense UI version may vary from each device.

Certain HTC devices such as Desire smartphones are still subjected due to some of models running Android ICS and Jelly Bean only. Flagships are always prioritised regarding software updates.

LG Smartphones and G Pad 8.3

LG G2 and G3 are likely the first on receiving Android 4.5 which may be followed later on by G Flex. Expect the new firmware to become as well for LG G Pad 7.0, 8.3 and 10.1 along with G2 Mini and G Pro 2.

It is unknown if LG will consider other models included in the Android KitKat such as Vu 3 and Optimus F Series. Most of these devices are still eligible due to software support window but LG has the right to choose which ones deserve it.

Motorola Smartphones

Moto X and Moto G are both eligible for the update and users may expect quick rollout just like with Android 4.4.3 KitKat. Additionally, Motorola hinted out that there is another new firmware update for Moto E but the company did not reveal what version owners can expect.

It is also obvious that these smartphones will bear the near-vanilla user interface from the next-generation Android version like with Android KitKat. There is no information yet from Motorola regarding the next major firmware upgrade for Droid Maxx, Droid Ultra and Droid Mini.

Nexus Devices

It is up to Google to decide if older Nexus devices are still eligible for Android 4.5. Nexus 4, Nexus 5, Nexus 7 2012 and Nexus 2013, and Samsung Nexus 10 are all upgradable to Android 4.4.2 KitKat but the support of Android 4.4.3 version has been extended to Nexus 4, Nexus 5 and Nexus 7 2013 only.

Depending on the final line up of Nexus devices, Android 4.5 may only support the following:

- Nexus 6

- Nexus 8

- Nexus 10 2

- Nexus 5

- Nexus 7 2013

Nexus 4, Nexus 7 2012 and Nexus 10 will reach the expiration of software support by the time a new Android version is announced.

Samsung Galaxy

There are several Samsung devices available in the market and the first batch for Android 4.5 will likely be the flagship models.

- Galaxy S5

- Galaxy Note 4

- Galaxy Note 3

- Galaxy Note 3 Neo

- Galaxy S4

- Galaxy Grand 2

- Galaxy Tab S

- Galaxy Tab 3

Other models which may be included on the second batch are Galaxy Note 10.1 2014, Note 8.0, Galaxy Note Pro and Galaxy Tab Pro. Galaxy S3 and Galaxy Note 2 are likely eliminated from Android 4.5 as Android KitKat would be their end of life cycle based on expired software support.

Sony Xperia

Sony Mobile will prioritise the models from Xperia Z series similar to Android KitKat upgrade plan. Moreover, some mid-range devices released in 2014 may be included but not the same case with devices released back in 2013.

- Xperia Z2

- Xperia Z1

- Xperia Z1 Compact

- Xperia Z Ultra

- Xperia Z1 and Z1S

- Xperia Z2 Tablet

Some units under Xperia Z series may end with Android KitKat such as Xperia Z, ZL, ZR and Tablet Z after receiving two major upgrades. Xperia T2 Ultra, M2 and E1 may also become eligible with Android 4.5 after Sony Mobile included them on Android KitKat plan. Sony Xperia SP is likely to end with Android 4.3 Jelly Bean or 4.4.2 KitKat.