I've not seen the texture manager class load textures by name rather than by location.
Another good thing to include is loading textures off a file, maybe the jME configuration file? Personally I would rather a seperate file.
I'm hoping that in future the texture manager class will be extended to do these things.
I've written my own in the mean time(which is not entirely generic).
Here's an example on how it's used:
TextureLoader loader = new TextureLoader(".\textures.txt", super.display.getRenderer());
obj = loader.getSprite("Water Tile");
obj2 = loader.getSprite("Wood Tile");