One of the most common complaints I keep hearing about the yet-unreleased next iPhone is a sense of dissapointment over its overly unchanged appearance, even if from the design standpoint the iPhone 5 is much more than a rehash of the existing iPhone 4/4S design.

Is you know, Apple’s upcoming device is said to sport a two-tone metal backplate (58 percent like it), a taller four-inch screen with new display technology, a relocated headphone jack and a much smaller dock connector with MagSafe-like functionality at the bottom.

But it ain’t just Apple. Nokia, once a leader in cell phones and now an also-ran, figured its inaugural Windows Phone 8 handset shouldn’t change the design formula established with the sleek Windows Phone 7.5-powered Lumia 710. Heck, if the above leaked photo is the real deal, Nokia may not be willing to change the overall Lumia design much with the new handset…

According to the Nokia Innovation blog, the upcoming Nokia phone has the same curved screen (though a bit bigger than the Lumia 900′s 4.3-inch display) and the same polycarbonate unibody form factor with irreplaceable battery.

It will also support 4G LTE, have an external SD card slot and NFC chip on board and will run on a Qualcomm chipset, making it the first dual-core Windows Phone 8 device from Nokia.

They call it the Nokia Phi and it’s one of three ‘hero’ devices set for an announcement at the Nokia World event in Helsinki, Finland, which runs from September 5 to September 6, just a week ahead of Apple’s planned September 12 iPhone 5 event.

For comparison’s sake, here’s what the Windows Phone 7-driven Lumia 800 looks like.

Notice any difference?

Me neither.

While Apple can afford to release an iPhone with virtually unchanged design (the iPhone 4/4S) due to its iconic status, the Lumia brand isn’t a household name (yet) so a totally different design might have been more prudent to promote this device as a ‘hero’ Windows Phone 8 handset.

One thing playing to Nokia’s favor: as the embattled company re-launched itself into the smartphone race in October 2011 with the Lumia range, feature phone owners are in fact hearing more positive buzz about the brand, according to a YouGov BrandIndex survey.

With about 50 percent of U.S. handset owners inevitably looking to upgrade to a smartphone at some point, their familiarity with the Lumia brand and perhaps an attractive postpaid push by the carriers could help re-establish Nokia’s presence in the U.S.

After all, prepaid devices seem to be increasingly becoming all the rage these days.

Would you consider Nokia’s upcoming Windows Phone 8 Lumia device?