Preview at WWDC likely in June, followed by September launch.
Photos of 4:3 Display from Apple's 'iPad Mini' Surface
Text on the back of the display suggests that the part was manufactured by LG Display, and text on the ribbon cable extending from the display is also consistent with labeling on genuine Apple parts.
ETrade Supply has also posted several photos of an iPad mini battery, which appears to be identical to the part shared by MacRumors earlier this week with the exception of the Apple part number. ETrade Supply's battery carries an APN of 616-0627, while the battery in our photo carried an APN of 616-0641. Any differences between the two parts are not immediately obvious.
Following ETrade Supply's posting of the iPad mini display photos, French site Nowhereelse.fr posted its own photo [Google translation] of what has been claimed to be the iPad mini display in quality testing. The site received the photo last week and was unable to verify with any degree of confidence that the part was indeed an iPad mini display, but with the actual part now having been shared by ETrade Supply, similarities in the mounting points for the two displays suggest that the display being tested may indeed be for the iPad mini.