I liked vanilla RTW, but I got bored of it in just a few months and once I discovered EB vanilla RTW completely lost its appeal.

It seems to me with CA's attitude lately is that they realize they made mistakes and they would like to fix them in Shogun 2. If that really is the case and it's not just hype then maybe Shogun 2 won't need modding to make it a good game. Modding would still be nice though. AFAIK CA hasn't said that it won't be modable, just that there won't be mod support, so I'm really hoping that maybe it will still be modable. As someone else (I don't remember who and I'm too lazy to read through the thread) already pointed out there hasn't really ever been mod support for TW games, so maybe there's still hope.