The RNC is the devil.
To my great surprise, I've been very accurate, in most cases getting every candidate in each race right to within 3 or less percentage points. The delegates are harder to predict due to some of the bizarre rules in some states, but I've been surprised at my accuracy there too.
If I maintain anything even close to that accuracy level, then I can safely predict that Trump will not get the 1237 delegates he needs, but instead come up about 150 delegates short. And Cruz will likely be another 200 delegates behind Trump. So, in my opinion, they are quite likely to form a team--it really becomes the smartest and easiest way for each of them to avoid disaster.