It's time for my conspiracy theory.
And please , no bitching. I am just stating what I think that might just be true. Now, you all know tite kubo. And you know that he has his ways of leaving small hints , especially by just having someone comment on litttle details. So here it it. I believe , for a great number of reasons , that Ichigo now has two bankai. Why ? Let's see... first of all , while there are other shinigami that wield two swords , their swords are identical , which is clearly not the case here. Second , the two other wielders refer to their swords as only one zanpakuto , but in Ichigo's case , they were referred to as " THOSE Zangetsu's ". Third , it's tite kubo. He isn't just going to show off his trump card just three or four chapters after Ichigo appeared... but he also put him up against eight guys... so , my guess is that each zanpakuto has its own bankai and that he is just going to show us the small one. Also , this might be pushing over the line already , but I think that he might even have a third one , which is the two small ones combined.