Preview at WWDC likely in June, followed by September launch.
White and Black iPhone 5 Parts Leak
The headphone jacks come in two colors: white and black, suggesting that Apple will be offering the iPhone 5 in at least the same two colors as they offer the iPhone 4.
Claimed iPhone 5 headphone jack parts
Apple has always produced black and white headphone jacks to maintain the consistency of appearance of their iPhones even on the small amount of the interior of the jack visible. For some reason, these parts (along with the sensor flex cable) seem to be amongst the first to leak. Similar parts leaked in the weeks leading up to the iPhone 4 launch back in 2010:
iPhone 4 headphone jacks leak
The camera lens replacement for the iPhone 5 sounded like it could be more interesting, but no details are offered for the part.
Apple had previously been rumored to be launching the iPhone 5 in white as well. The iPhone 4 was originally announced to come in both black and white, but production issues delayed the white iPhone 4 until the following April. The iPhone 5 is widely expected to launch in October.