@Metamario: If ure really looking for weird logic (A.K.A plothole) regarding the King's Realm, u've barely even scratched the surface. The more u think about it, the more it doesn't make any sense at all.
Fact: King's Realm is located in a separate dimension from SS and can only be accessed through special means.
The Special means:
1. The King itself granted u permission (which by the last chapter we can assume through the elevator)
2. Creating the key (in which Aizen chose, requiring hundreds of thousands of souls & a reiatsu-rich land)
But here we are presented with the fact that the elevator can be used to travel from the King's Realm to SS and NOT Vice Versa (u'll need an extra helping hand, which by the way, comes from the outcasts of SS). So the Soul King can't even let his own personal guards to enter his realm without their help?? Plus, I doubt that there isn't any record about it in any of the ancient scripts; I mean wouldn't it have been easier for Aizen to just manipulate the Shibas help and get him to the King's Realm? After all, Aizen is made to be a master a manipulation (he has been fooling the entrire SS for hundreds of years, plus that hypnotizing sword of his)
Secondly, if the method still requires the elevator to come, why bother making the key anyway? Why not just wipe out the entire SS EXACTLY the way the Quinzies are doing it? It should get the 0 Squad to come and Aizen can just beat 'em up. I mean, he declared war to the SS, that means he is ready to take on even the likes of Yamamoto. And he surely knows about the 0 Squad, so he knows he'll have to face them sooner or later. That means Aizen is confident enough to fight them, regardless of where.
But all in all, we can just dismiss it and say that it's in the nature of Bleach's villain to come up with an elaborate, intricate, extremely convoluted plans to achieve their goals. And I'll bet once Bach has revealed his true plans, we can see that there are much simpler methods to achieve it