Pencil LeBron for probably 27 or 28 million in 2016. Kyrie will be at 18, and Love would resign a max deal after this season in the neighborhood of 22. That's 67 million in salaries. If the television contract boosts the cap to 80 million, they have 13 million in cap room, plus whatever exemptions that would be at their disposal.
Frankly, I expect players to play hardball with the next CBA. They took it on the chin in the last one, and franchise values have gone through the roof, the TV revenue appears to be going through the roof, and I expect them to dig in their heels and demand a higher percentage of revenue. And if they prevail (even in a compromise), the cap goes up that much further.
This is all to say that in 2014 dollars, it doesn't seem like the Cavs could support 3 stars all making big money, but in 2016 and 2017 (and beyond) dollars, it seems much more feasible.