On the eve of a major Nokia product announcement, several leaks have detailed much of what the struggling smartphone maker is expected to reveal. And Nokia has other issues to contend with: Both Amazon and Google’s Motorola Mobility have scheduled events of their own for the same day. And Apple is widely expected to announce a new iPhone as soon as next week.

Nokia is holding a Windows Phone 8-related event in New York City on Wednesday, September 5, and is widely expected to announce at least two new handsets. This event runs concurrently with the firm’s annual Nokia World 2012 show, which happens September 5-6 in Helsinki, Finland. For this reason, the New York event is most likely aimed at a US audience only, and will most likely involve AT&T Wireless.

But in the days leading up to the show, bloggers and websites have apparently revealed much of Nokia’s expected announcements. The firm will unveil its next flagship phone, the Lumia 920, which includes a wireless/inductive charging option, a 1.5GHz dual-core processor, a 4.5" HD display, 1GB of RAM, 32GB of internal storage, and an 8-megapixel camera. Its form factor will allegedly be identical (or nearly so) to that of its predecessor, the Lumia 900.

Nokia is now also expected to unveil a Lumia 820. This device is a follow-up to the Lumia 800 and has nearly identical specs to those of the Lumia 920, but with a smaller 4.3" screen and, possibly, removable colored rear covers.

Given the relatively lackluster response to Windows Phone thus far, many are now referring to this new generation of handsets based on Windows Phone 8 as Nokia’s last stand. The theory is that Nokia’s falling fortunes can only be turned around with a decisive victory. But with Windows Phones selling relatively slowly compared with the market leaders, Android and iPhone, that possibility seems increasingly dim.

Not helping matters is the fact that the launch of Nokia’s new Lumias—and of other devices based on Windows Phone 8—is happening during a crowded launch window. Motorola Mobility, which kicked off the Android sales phenomenon with the original Droid, is expected to announce a new Verizon-based LTE smartphone with an edge-to-edge screen, according to Bloomberg. And Amazon will announce new Kindle tablets (and perhaps other devices—a Kindle phone has been in the rumor pipeline for months) on the same day.

And let’s face it: No one, not even the most popular Android makers (like Samsung), even want to think about the withering—if temporary—effects on Apple’s annual iPhone launch.

To help ease the transition, Nokia is expected to announce lower prices for its existing smartphones, which aren’t upgradeable to Windows Phone 8. And The New York Times reports that Nokia might try to entice Research In Motion (RIM) BlackBerry customers with encryption and security features that will be unique to its Lumia phones.

More Wednesday.