Now that has released Android 4.3, so begins the agonizing process of figuring out which phones tablets will get the upgrade, when. Not surprisingly, most Android phone makers are being cagey about their upgrade plans.

In response to a inquiry, a Samsung spokesperson told us that no plans have been announced at this time.

Meanwhile, a HTC spokesperson said “Now that has unveiled an update to lly Bean, Android 4.3, we’ll work to determine how this may impact our global region specific upgrade plans.”

Motorola hasn’t said anything about its upgrade plans yet, which is surprising given that the company is owned by . Earlier this week, the company announced a trio of new Droid phones, all running Android 4.2.

‘ve reached out to Motorola for additional comment, will update if we hear anything back.

Sony commits early

Sony

Sony’s approach is a breath of fresh air compared to other major phone makers. The company has already confirmed that Android 4.3 will be coming to the Xperia Z, Xperia Z Xperia ZR, Xperia S Xperia Z Ultra Xperia Tablet Z, though no specific timeline was given. Sony is also considering additional upgrades directly to Android 4.3 for some devices that are currently on Android 4.1.

Even better, Sony has pulled back the curtain on how the upgrade process works. In a blog post, the company explains in detail how hardware, software testing all factor in, discusses what parts of the process have improved over the years.

It’s often assumed that the major bottlenecks in the upgrade process are due to software customizations that carriers phone makers add on top of stock Android. But as Sony’s blog post explains, hardware is also a major piece of the puzzle, because phone makers need to spend time making sure all the components of their hsets work properly with ‘s software.

Fortunately, getting the hardware to a stable state with new versions of Android is a smoother process than it used to be. Sony says it collaborates more closely with Qualcomm with , whose atform Development Kit gives select phone makers a head start on upgrading their hardware.

Testing approval is still the biggest bottleneck, according to Sony. one makers need to make sure their upgrades comply with stards like Bluetooth, don’t infringe on other companies’ intellectual property run smoothly without disastrous bugs. “[I]t is not the Bring up phase, but the Test, certification approval phase that is the most time consuming process when it comes to getting a new software release out on our phones,” rik Ekstr, Sony Mobile’s head of software product management, said in the blog post.

A minor upgrade, at least

If it’s any consolation, Android 4.3 isn’t a major upgrade, many of Android 4.3’s features are already available on state-of-the-art phones like the HTC One Samsung Galaxy S4. Those phones, for instance, already support OpenGES 3.0 Bluetooth w Energy. The fact that Android 4.3 now supports these features just means they’ll come stard in many more phones to come.

The biggest Android 4.3 feature that users might want is Restricted ofiles, which will allow parents to create kid-friendly user profiles on their phones or tablets. But considering that many phones—including the HTC One—are still stuck on Android 4.1, any sort of upgrade at this point would be welcome. ke always, all we can do is wait.

Updated to include HTC’s statement.