One of the more controversial design decisions on the iPhone 5 was the change to the Lightning connector. In order to smooth the transition from the 30-pin Dock connector that had been in existence since before the first iPhone, Apple developed two adapters -- the US$29 Lightning to 30-pin adapter and the $39 Lightning to 30-pin adapter (0.2m) cable version. Macworld's Dan Frakes had a chance to do a hands-on with the adapters and has found that they're mostly compatible with existing accessories, with a few notable caveats.
Frakes notes that just about every audio dock or dock-cradle speaker he tested, whether old or brand new, worked with the adapter. Things weren't as clear-cut with some chargers due to the new pin arrangement, with some devices requiring a "kludge" arrangement that included a charging adapter from Scosche or CableJive.
When it comes to microphones or audio-input devices, the post cites an interview that Macworld's Peter Kim had with pro-audio company Line 6 in which he was told that "audio products that operate using USB Host mode and follow Apple approved methods such as CoreAudio and CoreMIDI" should work with the new adapters.
The adapters are now shipping to people who had ordered them, so we'll be able to get a much clearer picture of exactly what accessories work with the adapters and which do not. Until then, the Macworld post is a good way to get a feel for what items definitely won't work with your Lightning-equipped iPhone 5 and the newest iPod touch and nano models.