Mark Gurman, 9to5Mac’s teen blogging phenom, reported Friday that Apple (AAPL) is prepared to replace the iPhone and iPad’s Map app — built on Google’s (GOOG) back-end mapping data — with something entirely its own.

Its unveiling, according to AllThingsD‘s John Paczkowski, will be one of the highlights of the WWDC keynote on June 11.

“Here’s the thing,” Daring Fireball‘s John Gruber weighed in. “Apple’s homegrown mapping data has to be great. Mapping is an essential phone feature. It’s one of those handful of features that almost everyone with an iPhone uses, and often relies upon.”

So what will the new maps look like?

The assumption is that Apple will be using the talent and technology it acquired when it snapped up three mapping companies in the space of three years: Placebase in 2009, Poly9 in 2010, and C3 Technologies in 2011.

That last acquisition — a spinoff of Swedish jet- and automobile-maker SAAB — is particularly intriguing, given what its military-derived technology can do. There are several demonstrations of C3’s 3D-flythroughs on YouTube. We’ve linked to one in the image above (click it to view the video), and copied several more below the fold.

Of course, just because Apple can do something, doesn’t mean it will. The company is famously conservative in such matters, rolling out new features only when it feels they are ready for prime time (Siri, perhaps, being the conspicuous exception).

As Gruber points out, this is a high-risk switch for Apple:

“Regressions will not be acceptable. The purported whiz-bang 3D view stuff might be great, but users are going to have pitchforks and torches in hand if practical stuff like driving and walking directions are less accurate than they were with Google’s data.”

Those whiz-bang 3D demos:

Hoover Dam:

Oslo:

London:

http://youtu.be/Q5lM_KefDkg