Hueco Mundo...

[Wio]

So, how is it that if Sandle Hat has a way to Hueco Mundo, and Soul Society doesn't or isn't sending shinigami over to take out Aizen? I don't see what they are trying to accomplish with their current actions...

[Gjallarhorn]

All things considered, there Hollows have a way of going to and from Hueco Mundo, so all Urahara would have had to do is figure out how they did it. After all, he was the head of what was essentially Soul Society's R&D department. And, as for the Shinigami using it, I'm sure that they realize they aren't a match for Aizen and the Arrancar, and decided to bide their time and become stronger for when Aizen and the Arrancar finally attacked.

[WhatIsAUserName]

If you're asking why Soul Society isn't sending shinigami to Hueco Mundo, I just want to note that it's not like they can't, since Rukia and Renji made it to Los Noches.

Of course, there's always the fact that Los Noches is pretty much all the territory that Aizen has (it's not like the Hollows are taking orders from him), and I guess everybody is apprehensive about sending any forces to the stronghold of one of the most powerful people in the Bleach universe.

[Sogetsin]

My openion is the same as the others. I'm sure that if they thought they were strong enough to beat Aizen and the Espada they would go to Heuco Mundo. They're just getting more time to train to defeat him.

[Wio]

Originally Posted by Xero XIII

All things considered, there Hollows have a way of going to and from Hueco Mundo, so all Urahara would have had to do is figure out how they did it. After all, he was the head of what was essentially Soul Society's R&D department. And, as for the Shinigami using it, I'm sure that they realize they aren't a match for Aizen and the Arrancar, and decided to bide their time and become stronger for when Aizen and the Arrancar finally attacked.

This is the only opinion that held water for me. Still, Aizen is getting stronger. Usually you want to attack someone before something like the Hyoouga is made.

[Mugetsu]

The shinigami are aware of how long it will take for Hyoouga to be fully awakened/activated. They are using this time to prepare for the all out war with Aizen and the Hollows/Arrancar. After the defection of 3 of their captains Soul Society was in confusion. If they went after Aizen without making proper preparations they would get demolished. Hollows/Arrancar are stronger in Hueco Mundo than they are in the material world or in Soul Society.

You can see an example of this from what happened to Chad when he went to Hueco Mundo. He got stronger and got armor on his other arm. Plus you never really want to attack your enemy on their home turf if you can avoid it. You leave yourself open to traps and tactics that you don't expect. At least this way they can asses what they are dealing with and get stronger.