The Mountain West has been considered a mid-major in football and basketball for the last decade or so. In football, the league was on the verge of being considered a major conference, joining the "Big Six" and possibly getting an automatic BCS bid.
But their AQ hopes for football fell through with the loss of BYU and Utah, and the same move probably reduces the league from mid-major to minor conference if you define that status by NCAA bids.
There are many competing definitions for "mid-major." But if you look strictly at at-large bids, BYU and Utah remove a lot of the Mountain West's pull.
NCAA at-large bids, 1999-2011.
Conference prev current ave
Big East 82 82 6.3
Big Ten 60 60 4.6
Big Twelve 58 58 4.5
SEC 57 57 4.4
ACC 50 50 3.8
Pac-12 46 50 3.8
Atl Ten 21 21 1.6
CUSA 13 13 1.0
MVC 13 13 1.0
West Coast 7 12 0.9
WAC 10 10 0.8
Mtn West 16 7 0.5
Colonial 4 4 0.3
Horizon 3 3 0.2
MAC 1 1 0.1
Sun 1 1 0.1
Big West 1 1 0.1
Note: "Prev" = 2011 conference alignments
There is a clear dividing line between the major conferences (50+ at-large bids) vs. the non-majors (21 or fewer). It's less clear what a mid-major is as opposed to a minor conference, but teams averaging one or more at-large bids (rounded up), i.e., those in the double-digits, are what we'd call mid-majors. In other words, if a conference can be expected to get more than just their automatic bid (normally the conference tournament winner) are mid-majors.
Note that the Mountain West, inclusive of BYU and Utah, is very clearly a mid-major, with 16 at-large bids in 13 years (and technically they had no automatic bid in 1999, so you could say the number should be 17—but we treat their bid as automatic). Without BYU's 5 at-large bids during that time span, and Utah's 4, the MWC falls to just 7 bids in 13 years. That either makes them the weakest mid-major or the strongest minor conference. By our definition, they are the weakest mid-major conference.
The biggest beneficiary is the West Coast Conference, which goes from a borderline mid-major to a very solid mid-major with 12 bids in the last 13 years with the Cougars on board. The Pac-12 also improves from the weakest major to a tied for that designation with 50 at-large bids in the 13-year range.
Performance-wise this year, the MVC is a major conference
Ironically, despite the loss of two of their traditional powers they are having their best season in years. BYU is doing well in the WCC at 18-5, but this season the loss of Utah means nothing as the Utes are struggling at 5-15. Meanwhile San Diego State, UNLV, and New Mexico are all as good or nearly as good as they've been recently, while Wyoming is solid 16-4. The other four members all have winning records as of January 27, the only conference that can boast that.
As a result, the Mountain West's conference RPI is currently #5. Ken Pomeroy's ratings put them at #6, as do Jeff Sagarin's conference rankings. That's in the "major" status territory. The MWC is ahead of the Pac-12 by all three measures, and even ahead of the ACC in the RPI. While the transfer of Utah to the Pac-12 was a bad thing by historical measures and cumulative NCAA at-large bids, for current performance it was a boon for the MWC, handing the Pac-12 a cellar dweller.
And using NCAA bids is a sore point for the conference, which has been burned in the past and treated more like a minor conference, getting single bids many years when some observers have though they deserved better. Evidence of this was outlined in the Dance Card research by Jay Coleman, Michael DuMond, and Allen Lynch.
Conclusion: Mountain West still a mid-major—for now
The Mountain West will get from 2 to 4 bids this year, with 3 seeming most likely right now. UNLV and San Diego State are pretty solid, with high RPIs. New Mexico's RPI is borderline but most projections put them in. Colorado State and Wyoming are weaker candidates but still have a shot.
If they get three bids, i.e. two at-large, that would be 11 at-large bids in 14 years which keeps them fairly solidly in the mid-major designation by the NCAA-bids method.
But the future looks dim as conference realignment strikes again. San Diego State, one of the bright spots of the last few years, is moving to the Big West in a few years. TCU and Boise State are leaving, which hurts football a lot more than basketball but still leaves the conference depleted. Even with the influx of a few WAC teams, the conference will be down to seven members as things currently stand.
Given the Mountain West's 2012 RPI and performance, the selection committee might treat them as a near-major conference, but in the years to come they'll start to look more like a minor conference. Given the selection committee's track record with the MWC, don't be surprised if they are soon back to being a 1-bid league.