While this seems like this should go without saying, because of all the questions we've been getting, and posts we've been seeing, iMore reached out to the original sources that gave us the new Dock connector story way back in February just to make doubly sure -- and yes, there will be an adapter for the iPhone 5's smaller Dock connector that will let it work with many of the accessories designed for the old 30-pin Dock connector.
We haven't heard if one will be included in the box along with the iPhone 5, or will only be sold separately, but either way, come October, you'll be able to get a new-to-old Dock adapter from Apple.
Apple has done this recently with the MagSafe to MagSafe 2 adapter, and in past years with a variety of other display adapters. Of course, there will likely be some accessories that, due to the physical size or shape, are awkward or impossible to use with the Dock connector adapter, but anything that doesn't require tight, flush contact should be okay
The reasons for the new, smaller Dock connector remain the same as what we outlined back in February -- Apple needs additional space inside the iPhone 5 casing to fit an LTE chipset and the battery to go with it. It's the same reason they're rumored to be going with the nano SIM, and perhaps an in-cell display as well. Every millimeter and milliamp matters.
Also, thanks to features like iCloud and PC-Free, as well as Wi-Fi sync and AirPlay, the Dock connector doesn't need to do everything the way it used to. A lot of the connectivity can be offset to wireless.
Apple is still on track for a fall release for the iPhone 5, and last we heard that was October. The new, smaller Dock connector will debut at the iPhone 5 event and be used in all iOS devices from then on out. (Including the rumored 7-inch iPad.)
But rest easy, and certainly don't throw anything away -- it'll have an adapter.