I'm really sorry for reviving this thread and I know that this is REALLY old but I am still yet to find a decent blp to png converter that actually preserves the transparency. Everytime I use xnview to convert the files, it always makes the background black :(
I have tried wowimage BLPPNGBLP, xnview ofc, blp2viewer and still nothing that works properly :(
Does ANYONE know of a decent utility that can be used to convert a BLP properly??