Is the iPhone a Phone, a Computer? Or Both?

In explaining why SlingPlayer for the iPhone won’t include 3G support, AT&T (s T) broke new ground, equating the Apple (s AAPL) device with PCs. “We consider smartphones like the iPhone to be personal computers in that they have the same hardware and software attributes as PCs,” the carrier told Engadget Tuesday night. The carrier defends its 3G blockade of the TV streaming app by pointing to its terms of service, which specifically prohibit redirecting “a TV signal to a personal computer.” However, the explanation departs from other handsets, such as RIM (s RIMM)’s BlackBerry Bold and other Windows Mobile phones that permit SlingPlayer, according to Slingbox.

So is it a phone, PC, or both?

Indeed, AT&T’s argument appears to go to the heart of our message earlier this week that the iPhone won’t destroy wireless carriers. AT&T has a love-hate relationship with the iPhone, acknowledging the handset is responsible for increased revenue, yet fearful its 3G network might crumble under the higher bandwidth from iPhone users. As MediaMemo interpreted AT&T’s statement, “If we give people the chance to watch TV on the iPhone, they’ll flock to it –- and our network can’t handle that.”

Along with questions about the sturdiness of AT&T’s 3G network, Kevin Tofel over at sister site jkOnTheRun feels the “crippled” SlingPlayer iPhone app returns us to issues of network neutrality.

But AT&T may have also inadvertently rekindled the argument over whether the iPhone is more like a netbook than an iPod with telephone features. Apple CEO Steve Jobs drew the original comparison in 2008 when the iPhone 3G was released, telling the Wall Street Journal “there’s been nothing on a mobile phone a fraction as good as what’s on PCs.”

This isn’t the first time carriers have wanted to rein in the iPhone. Earlier this month, reports surfaced that Microsoft (s MSFT) would ban VoIP applications from its upcoming Windows Mobile Marketplace, a move seen both responding to carriers and preventing a repeat of Apple’s episode over a Skype app available through the iPhone App Store.