Two year campaign?
Blame California, which (as I believe I heard) just today moved its primary from June to February. Several other states with large electoral votes (thus, large delegate numbers at the party conventions) are moving to do the same, on the same day, February 5... including the state I live in.
The campaign for nomination now has less than a year to run, considering that it could be decided on that fateful day, months before the conventions seal the deal.
The campaign for the office of President will be lengthened accordingly, of course, but they are tactically and strategically two separate efforts.