According to benchmark results for the upcoming Samsung Galaxy S4 Mini, the device will make use of a Qualcomm Snapdragon S4 Plus processor and feature a 6-megapixel camera. The Snapdragon S4 used is a dual-core part clocked at 1.7GHz and it features an Adreno 305 GPU. These are a bit under-powered compared to its larger brother.
The S4 Mini should be running Android 4.2.2 with Samsung's TouchWiz placed on top. Pictures will reportedly come via a 6-megapixel camera, though this exact specification hasn't been detailed. Techtastic is drawing this conclusion based upon pictures on Picasa that are reportedly taken with the S4 Mini.