Within the Pac Ten "footprint" (Pacific and Mountain Time Zones) the following schools are ranked by research:
Research/Very High and AAU member (Stanford, Cal, USC, UCLA, Washington, and Arizona rank here)
Colorado
Research/Very High (Arizona State, Oregon State, and Washington State rank here)
Utah
Colorado State
New Mexico
Hawaii
Montana State
Research/High (Oregon is in this category, despite being an AAU member)
BYU
UNLV
Wyoming
San Diego State
Texas Tech
Nevada
Utah State
UTEP
New Mexico State
Idaho
Montana
Doctoral Research
TCU
Masters (Large University)
Boise State
Fresno State
San Jose State
Athletically, I think the Pac Ten isn't solely motivated by football, and probably look fairly well upon UNLV and UNM basketball. The difference between the two universities is that UNM is sinking a lot of $$$ into their athletic facilities ($60 million renovation of The Pit, and 42,000 capacity for the football stadium) over the last few years. While Albuquerque isn't Las Vegas, the higher academic research standing, generally considered higher academic programs, better facilities (UNLV's last AD complained bitterly about this), and much greater community support the Lobos should easily get the nod over UNLV for any conference expansions (and could have leverage with both Pac Ten and Big 12 footprints bordering their state). There is some historical rivalry with Arizona as well, as both states were carved out of the same territory after the Mexican War.
I can't see the Pac Ten dropping their academic standards to allow BYU. BYU is a GREAT under-graduate school for certain degrees, but the academic freedom issue and lack of high research activity are deal-killers to me.