The latest rumor circulating out of Taiwan via Commercial Times is that Apple’s slim designed battery requirements are not being met and the 5.5″ iPhone 6 release may be pushed into 2015. It was previously reported that there was difficulty producing the 5.5″ touch panel displays and that the displays would like be delayed a few months.
At this point I’m chalking this up as another rumor that may or may not be accurate. At one point various speculation was made that the 5.5″ handset would be released first and now rumors are pushing the release into 2015. I would have expected Apple to clear the battery thickness requirement during early beta testing and product design requirements. Stay tuned on this one as this story may update again.