Western Michigan has stated they are happy and want to be in the NCHC, where Miami's coach has stated he didn't want Miami in the NCHC before he took the BGSU job.
At some point the NCHC will expand, but will take teams that benefit the conference. St. Thomas looks good because they are in the twin cities and that could bring more people to the Xcel.
10 to 12 teams is about the right size of the conference. With that many teams the NCHC could be getting 5 to 6 teams in the NCAA tournament each season which is good for the conference.