I think that both Killer instinct and Storm442 hit the nail on the head. With all the new organizations out there the competition is getting watered down. Its like expansion in any other sport. The more teams you have the lower quality product you put on the field.
Also with a very stacked LW divison right now the UFC needs to keep hyping that up and get a solid core of fighters and some good prospects before they even consider a 145 division.
Right now the LW division is arguably the best/most exciting division in the UFC top to bottom. Let that ride for a while before they dismantle it.