Hatsune Kagami makes another appearance, in an older and extremely hard to find image (if you come accross the original, please do share it), but one which is rather appealing. There are some other incarnations below, but for more we will likely have to wait until the OVA features her (probably only for scant minutes at best).
As you can see, the excellent original here has undergone some Mikufication.
Others I picked up in my search. Scant consolation?