On 31 October, Google unveiled the much anticipated phone Nexus 5 along with the brand new OS v4.4 KitKat. Soon after the announcement, many Android OEM (Original Equipment Manufacturer) smartphone partners have promised to release the new OS update soon.

Here is list of the top devices which are slated to receive the Android KitKat update:

Nexus Devices:

Google affiliated 'Nexus' devices have always had the privilege to receive the new OS update among all android gadgets. Hence with the tradition, Asus's Nexus 7 (2012 and the 2013 editions), Samsung's Nexus 10 tablets and the LG's 2012 model Nexus 4 smartphone are expected to receive the OS within a fortnight's time.

Motorola:

Motorola, now owned by Google is reported to push new KitKat OS update to four-smartphones- Droid Ultra, Droid Maxx, Droid Mini and Moto X. However, the company is still tight lipped about when the OS will be released, reported DroidLife.

HTC Devices:

The search engine giant has confirmed to push new OS update to HTC One Google Play Edition (probably by mid-November).

Bringing a cheer among fans, the HTC (USA) tweeted that the KitKat firmware (with Sense v5.5 UI) will be rolled to the original HTC One (locked and unlocked versions) in 90 days.

Technology website, Engadget has reported that the Taiwanese company is also planning to release the update to the HTC One Mini and the recently launched HTC One Max phablet soon.

[Update:HTC has revealed that the company is planning to release new KitKat OS update with Sense 5.5 UI to HTC One in EMEA (Europe, Middle East and Africa) regions by the "end of January 2014".]

Samsung Devices:

Among Samsung devices, Galaxy S4 Google Edition which is currently sold in US is confirmed to receive KitKat OS update in couple of week's time.

As of now, Samsung's original Galaxy S4 which runs on Android v4.2.2 OS with TouchWiz Nature UI out-of-the box is receiving v4.3 Jelly Bean across the globe. Rumour has it that Samsung may push KitKat update to 2013-models Galaxy S4, Galaxy Note 3 and others in early 2014.

Samsung's 2012 marquee devices- Galaxy S3 and Galaxy Note 2 are expected to receive v4.3 Jelly Bean by the end of the year.

Sony Devices:

Japanese major, Sony also has some good news for its loyal Xperia smartphone fans. Sony tweeted that the company would reveal the list of products eligible for the v4.3 Jelly Bean as well as new KitKat OS update.

Company's 2013 models-Xperia Z, Xperia ZL, Xperia ZR, Xperia Tablet Z, Xperia SP and Xperia Z Ultra are already slated for v4.3 update, but with KitKat OS announcement, Sony may skip v4.3 and go for the v4.4 update. Xperia Z1 is the top contender to receive the new KitKat OS firmware soon. 

[Update: Sony, though not defining any time-line, on 7 November has confirmed that the new v4.4 KitKat firmware will be released to the company's select (five) marquee devices- Xperia Z, Xperia ZL, Xperia Tablet Z, Xperia Z Ultra and Xperia Z1.  ] 

 LG Devices:

So far, the South Korean firm has not revealed any details of KitKat OS updates for its devices, but LG being a partner of Google's Nexus 5 and Nexus 4, the company is certain to release new OS updates for at least 2013 flagship models LG G2, G Pad and G Optimus G Pro soon.

Here is the key enhancements brought in to the v4.4 KitKat OS

Improved Caller-ID: If a caller receives a call from unknown number, the phone will look for matches on the net with local listings via Google Maps.

Priority Contacts: The new OS empowers the phone to automatically prioritise contact list for easy access, based on the frequency of the peoples' contacts to which users talk.

Immersive display: To enhance entertainment factor, the new  OS comes with immersive mode, where the status bar and navigation buttons disappear in to the back ground while you play music, games and read e-books. Users can just swipe the edge of the screen to bring back the utility buttons.

Enhanced Message grouping: taking a leaf out of Apple's iMessage feature, Google has brought in some improvements to the new Hangouts app; now, users can find all their text SMSs and MMSs, audio and video call details all at one place. They can also share location and send animated GIFs.

Emoji Characters:  Initially users had to install third party app to use colorful characters in their SMS. Now, with KitKat, the keypad comes with native Japanese Emoji emotion icons.

Voice Search: Google has brought in Google Now, a voice based search system, which we saw on the recently released Moto X. Users can initiate phone with voice command 'Ok Google' and then can initiate web search, play music tracks and even call people without having to touch the screen.

NFC and Wireless Printing: Google's new OS comes with improved Quickoffice app where-in people can create and store word documents online as well as print files wirelessly on NFC-enabled HP printers.

Bluetooth MAP (Message Access Profile):  This feature enables android devices in cars with Bluetooth support to exchange messages.

Multi-tasking:  with efficient memory management, users can multi-task by opening multiple applications; Listen to music while you can browse through the net.  

Performance: with low system requirements the new KitKat OS is expected to bring performance enhancements and also increase battery life.