Motorola Droid Bionic with its 4G LTE support is expected to be the biggest threat to the upcoming iPhone 5.

However, with Verizon grabbing one-third of all iPhone 4 sales and AT&T selling three times as many iPhone 4 units currently, it surely has paved the way for the upcoming iPhone 5.

The key reasons why iPhone 5 will beat Motorola Droid are:

iOS 5 will launch this fall, alongside iPhone5, delivering a great operating system with improved notification system, iCloud integration, iMessaging a bunch of other cloud based services. MobileMe services will give every iDevice holder free access to Apple’s cloud email, calendar and storage service.

iPhone5 will have a larger display than before with a 3.5 inch screen and a higher resolution retina display. Motorola Droid Bionic comes with a 4.5 inch display, which makes it like a small tablet.

iPhone 5 will be powered by the same processor that powers iPad2. Expect to see a 2x boost in CPU performance and a 9x boost in graphics. The A5 processor delivers more power than iPhone4 and once the App developers pay attention to it, there will be greater apps than Droid Bionic.

Droid Bionic will have a dozen cases, docks and cradles; but iPhone 5 will have thousands of choices of third-party accessories.

Motorola Droid Bionic will only be available on Verizon. iPhone 5 on the other hand will be available on Verizon and AT&T and is also rumored to come on Sprint, where you can get unlimited data plans for attractive prices.

iPhone5 is also rumored to be empowered with NFC support, so it would allow their users to pay for products via mobile payment.