I really want to find Tousen's quote that I loooove so dearly, then I'll make my point.
http://www.onemanga.com/Bleach/178/13/ <3 Dear love.
But yeah, shoot.. I forgot my point >< :'D *improvises*
The path not dyed with blood, following Aizen into the depths of HM, staying by his side till the very end for an unknown reason, it's very possible he could betray him. Not to mention his friend that he mentioned way back, we don't know who that is, may have some relation to it.