Verizon, Sprint and T-Mobile are in a constant battle of ‘one-upmanship’ to bring their customers the best Android phone.  Depending on your tastes, Verizon and T-Mobile are probably in the lead right now.  T-Mobile has the Android 2.2 OS, hacker-friendly Nexus One while Verizon has the HTC Incredible and still sells the Droid slider with hardware keyboard.

Sprint, not to be outdone, launches the EVO 4G next week, which blows away the specs of just about any phone out there right now, announced or unannounced.

But these carriers all have multiple Android devices, for different customers’ tastes.  T-Mobile has 10 Android phones including the Nexus One sold through Google.   Verizon has five and can’t stock the Incredible fast enough.  Besides the EVO, Sprint (S) carries the HTC Hero and Samsung Moment.

AT&T?  Currently if you browse their site, you come up with just one Android phone.  The Motorola Backflip (check the ratings) which isn’t impressing anyone with its Android 1.5 OS (Motorola says it can be updated to 2.1 if/when AT&T decides to do so) and 320×480 screen.   Oh, and it is bundled with Yahoo search, which replaces Google’s search engine.

Frankly, to me it looks like a knockoff iPhone from 2008.  They’ve got what appears to be another cheap knockoff iPhone in the Dell Aero next in the pipeline.  It is also will run an already outdated Android 1.5 Cupcake and is advertised as having ‘Flash lite‘.  How 2008.

Those aren’t the only Android phones you can get working on AT&T’s network however.  Google made a special version of its flagship Nexus One that works on AT&T’s 3G network (unlike the T-Mobile version).  Also unlike T-Mobile, AT&T refuses to subsidize Google’s (GOOG) Nexus One.

What’s going on here?  Surely AT&T (T) would love to pick up some high end Android users?  Nope, no love.

I personally think the problem is Apple (AAPL).  AT&T has wanted to keep Apple’s exclusivity in iPhones and iPad 3G devices and the best way they know how is to avoid high-end Android phones that can compete and even, in some ways surpass the iPhone 3GS.

I’m not insinuating that Apple and AT&T have some sort of deal to block solid Android devices, I’m just saying it is in AT&T’s best interest to remain iPhone focussed on the very high end.

Recently, AT&T’s Ron Spears, CEO of the telecom company’s Business Solutions unit, told a ZDNet reporter that they hadn’t seen much Android adoption in the enterprise.

The next question for Spears revolved around whether the enterprise was also looking at Android. Keep in mind that AT&T hasn’t really had an Android lineup for long, but Spears said, “I haven’t seen the Android platform yet in the enterprise space. Not to say it won’t come, but pretty much that platform has been built with a very specific focus to consumers. Over time, my guess is there will be an evolution that’s kind of hard to ignore the enterprise space.”

Is that surprising when AT&T just started carrying its first Android phone and it is more than a few generations behind in OS?  I imagine that companies that use Google Apps would be very interested in Android phones, especially ones that get updated to the latest Froyo OS which got 22 new business and enterprise features like remote wipe and full native Exchange support.

But is all that about to change?  Dell’s new 5-inch  mini-tablet/monster phone, called the Streak,  is rumored to be heading to a US GSM carrier in late Summer.  That is either T-Mobile or AT&T.  The UK version will use AT&T radios so that skews it in AT&T’s favor.  AT&T also carries Dell’s only other phone, as mentioned above.

Also, AT&T is rumored to pick up a pretty impressive  Samsung i897 according to AndroidGuys (pictured below).  This is in the same class as the Nexus One and the HTC Incredible.

An even bigger mystery phone is also rumored to be hitting AT&T on a very interesting date: June 7th.  Very little is known about the Aria, but it had better be pretty good if it wants to overshadow the iPhone 4/HD announcement at WWDC.

The specs of these two phones put them in a class with the Android superphones mentioned above from the other carriers.

So why the big delay?  Maybe AT&T was just late to the Android game.  They were also the third carrier to pick up the Palm Pre.  But it’s hard to overlook the ‘Apple effect’.

There is also AT&T’s fights with Google Voice over rural carrier blocking that may have slowed down cooperation.  AT&T and Google are also at odds over Net Neutrality.

The biggest factor however, is that AT&T’s exclusivity on Apple’s products is also coming to an end and AT&T has no reason left to impress Apple.   Will that lead to a flood of new Android phones?

AT&T commented for the story by saying, “We remain strongly committed to Android.  As we said at CTIA, we have a number of really great devices that you’ll see in the very near future.”

These next few months should be telling.