Revamped headphone jack may prevent iPad 2 moisture
An iPad 2 teardown on iFixit.com shows a headphone jack redesign that allows for the thinner hardware and possible weatherproofing.
Based on the iPad 2 teardown graphics sourced on the crowdsource repair manual site iFixIt, he speculates that the new headphone jack is the materialization of a patent Apple submitted back in September 2010 that uses smaller pogo pins instead of the traditional metal strips.
The springy pogo plug design reduces the real estate required around the hardware, and also exposes the outermost plug ring when fully inserted into the jack--not a big deal, since the "ground ring" is simply used to remove charge and pause device playback when you remove it from the connector.
Interestingly enough, Fox also speculates that its steep-angled curve within the iPad 2 suggests a weatherproofing element to prevent moisture penetrating the device, and the subsequent lawsuits that can occur as a result.