Haha, yeah, Aizen just said in the manga "our 20 friends," so I assumed they were vasto lordes, but was he including Grimmjow and the other arrancar? Is it ever stated exactly how many he has?
I dunno. I haven't been able to watch any eps since then. I'm assuming he meant vasto-lordes.It could be fellow arrancar. I'm not far enough to tell you anything yet...Right now the bald guy is facing an arrancar.