Sony's flagship smartphone, the Xperia Z3, is no longer for sale by wireless carrier T-Mobile, and there's no note of explanation forthcoming from T-Mobile or Sony, for that matter.

The smartphone had been available for less than a half a year, and some reports claim its quiet withdrawal from the competitive market place reflects the work Sony has ahead to become a force in the smartphone market.

The disappearance of the Z3 may also have something to do with the fact that Android Lollipop, the latest Android mobile OS, is just starting to become available for the handset, nearly six months after the Xperia Z3 landed in T-Mobile's store. Smartphone consumers are a persnickety customer base and they expect OS updates as fast as they hit the scene, especially when the update is already in the hands of competing device owners.

However, most reports believe the quiet move by T-Mobile to pull the Xperia Z3 simply reflects a very low consumer demand for the smartphone.

Meanwhile, despite hype and sneak peeks in the past month, there's no update on the arrival of the next generation, the Xperia Z4. What the disappearance of the Z3 means for the Z4 is anyone's guess at this point. It could be Sony just wiping the market slate clean for the latest device generation or it could indicate there is no Z4 coming to market despite lots of hype in the past four months.

The impending latest flagship device appears to have a very similar look and internal features though it reportedly will boast the Snapdragon 810 from Qualcomm, a quad-HD display, 3 GB RAM and two cameras. Sony has stated it is reviewing its smartphone lineup strategy and most likely focusing on the high-end market segment.

As Tech Times has reported, Sony is also mulling a potential sale of its smartphone business as part of its product assessment and market strategy.

While T-Mobile is busy pulling a Sony flagship handset off its website, Sony competitor Apple is prepping three new iPhone handsets set to arrive in the second half of this year: the iPhone 6s (4.7-inch), iPhone 6s Plus (5.5-inch) and the all-new iPhone 6c, which features a 4-inch display.

Back in early 2015, Apple CEO Tim Cook said his company is enjoying the largest "switch" rate of Android users to iOS device users in the past three years. It might just have something to do with the direction Apple is moving and the direction competitors, such as Sony are moving.