I think it'll probably be best to wrap this up into a small standalone library that can be used with LWJGL.
I say this mainly because there are already a few options available for loading textures like MatthiasM's PNGDecoder and JPEGDecoder, Slick-Util, Devil, JME (also has its own classes), Ardor3D (also has its own), AWT, etc.
So to remain lightweight and neutral best to avoid having such a thing directly inside LWJGL. You could however link it up on the LWJGL Wiki and write a tutorial or two on there so users can easily find it and use it with LWJGL.