Update: We’ve been told by a source at AT&T that those micro-SIMS are for the forthcoming Pantech Burst and Element which are also on the way to AT&T this week.

A regular AT&T SIM card (left) and a 4G LTE Micro-SIM (right). Click for larger.

A new batch of Micro-SIMs arrived at AT&T stores. We would normally pass on the news—if those were normal non-miniaturized 4G LTE Micro-SIMs. Based on an anonymous tip, Phone Arena noted AT&T now getting LTE Micro-SIM cards “could be an indication that the next iPhone will finally support 4G LTE connectivity.” If you ask us, those are likely for the Nokia Lumia 900 that is hitting the AT&T network on March 18.

Granted, it is not entirely out of question that AT&T LTE Micro-SIMs are in anticipation of a sixth-generation iPhone that is presumably scheduled for an announcement this summer. Apple was the first major handset maker to switch to tiny 3G SIM cards with iPhone 4, which was a move born out of necessity due to space constraints in the 9.3mm device. The iPhone 4/4S are the only Apple products compatible with the Micro-SIM standard.

What about the iPad 3, you ask….

We can only speculate at this point, of course, but it would make sense to use the smaller Micro-SIM and save some space inside if the iPad 3 is a 4G LTE device. Why is that important? Well, Apple will likely add some extra battery capacity to power the iPad 3’s “truly amazing” Retina Display without sacrificing its legendary 10-hour battery life. A bigger battery will apparently make the next iPad just a tad thicker, so space will definitely be at premium. Do not forget that the radios for LTE will also add some weight, so an LTE Micro-SIM instead of the regular SIM card sounds like a prudent move.

As iPad 3 parts begin floating around, the rumor-mill is calling for an early-March announcement based on a tip by AllThingsD.

  • Japan rumor: LTE iPad 3 coming in summer 2012, LTE iPhone 5 in Fall (9to5mac.com)
  • What DON’T we know about the next iPad (besides its name)? (9to5mac.com)