I think you have to realize the economics involved.
Loveland closes earlier than A-Basin because A-Basin is in a better position to attract more late season guests through the Epic pass. Maybe in the pre-Epic era they could have pushed harder to draw in the May-June skier, but now that has run its course. Making money on May-June operations is a dicey proposition, because growing that pool of skiers is very tough- they would have to steal those skiers from A-Basin, and what you would have to discount in order to do so likely puts you in the red. If you fail, you are in the red not just for May-June operations, but possibly for the entire season from a quixotic quest to stay open as long as snow conditions allow.
Both Loveland and A-Basin race to open first. However, they both do not blow snow the instant temps drop to freezing. It costs a lot of money to make snow, and the last thing in the world you want is to start too early, drain your reservoirs and run up your electric bill, just to have warm weather melt off your product. Water is a finite resource, and it can mess you up for the entire year if you waste that water on melted snow trying to open in September. Again, this decision can easily move the entire year from being profitable to being a loss. If they burn through their water, and the result is not a lot of open terrain, people don't come.
They look for a long period of good snowmaking temps before they start. Loveland's snowmaking clock is marketing. If good temps show up, they start making snow. If they don't they wait. Ditto for A-basin.
As to who will open first, it depends on what you define as open. Does 1 day count? Does weekends count?
Several resorts are perfectly willing to open for a weekend if they get hit. Mt Baker did this last year in Early October, I believe. Wolf Creek opened on a weekend schedule October 19 last year, just a few days after A-Basin. On all-natural snow to boot.
Wolf Creek surprised everyone 2011-2012 by opening October 8 after a monster storm, beating A-Basin and Loveland to the punch.
There is some bump in MN that will open with 3" of snow on grass if they get the 3".
So really, you have the established guys that blow snow to open 1 run as soon as they can (Loveland and A-Basin). Then you have wildcard management all over the country that won't blow snow, but will be happy to open the mountain if weather permits.
Then you have the other guys that won't open even if they have the snow. Purgatory (DMR) has done this game for years. Last year they had enough snow to be 100% open mid-November and they refused to open (while still releasing waist-deep November stoke pics to the press). The year before, they had a horrible beginning of the season until they got about 40" the week before Christmas that allowed them to open almost all of the mountain...
Only they let that snow sit for a week until the Christmas crowds came to open up terrain. And they wonder why locals have stopped buying passes...