Each item in the unix filesystem can be one of the following: file, directory, symlink, device node, socket, fifo.
So nothing's stopping you from making it a normal file and capturing all the output programs send to it.
For super funsies you can make it a symlink or socket, but I think most programs won't work if it's a socket.
Nothing also is stopping you from removing it and mknod'ing a /dev/null into another device file, such as the one /dev/full or /dev/zero uses, or /dev/fb0 if you wanna be really silly.
So nothing's stopping you from making it a normal file and capturing all the output programs send to it.
For super funsies you can make it a symlink or socket, but I think most programs won't work if it's a socket.
Nothing also is stopping you from removing it and mknod'ing a /dev/null into another device file, such as the one /dev/full or /dev/zero uses, or /dev/fb0 if you wanna be really silly.