It's quite possible that Apple itself doesn't yet know when the iPhone 6 will be announced, since there are so many factors involved in ramping up production for the huge number of devices that Apple sells.
Still, the latest rumor, reported by MacRumors and citing someone who got information from an internal Apple retail meeting, is that Apple will announce the iPhone on September 16 and begin selling it on October 14. While the September 16 date fits with expectations, the arrival of the phone a month later is atypical because Apple usually comes out with a new device about 10 days after the announcement. Also, Apple has almost always begun sales on a Friday, but October 14 falls on a Tuesday.
The source cited by MacRumors didn't give any indication whether the 5.5-inch iPhone would also be announced, but the evidence continues to suggest it will arrive later. The good news is that photos of parts for the 5.5-inch "phablet" have begun to appear online, indicating to me that we will indeed see the device this fall. One such part can be seen on AppleInsider, which has a photo that shows side by side the logic boards from an iPhone 5s, 4.7-inch iPhone, and 5.5-inch iPhone.
Another big question is when we'll see Apple's forthcoming wearable device, the so-called iWatch. A report on AppleInsider, citing market analyst Ming-Chi Kuo (who often has solid inside information), says that the iWatch may not arrive until the December. Kuo says that many issues have arisen in the production of the device, which isn't surprising for a product in a new category, and that manufacturing may not begin until the second half of November. He even predicts that half the watches will ship with glass rather than sapphire, given bottlenecks in the production of the material. AppleInsider says that one issue may be the use of an AMOLED display in the iWatch, a technology that is new to Apple.