The problem with talent trees is that, counter perhaps to intuition, more talents mean less real choice. The more talents there are, the closer to impossible it becomes to balance them, especially when inter-talent synergies come into play. That leads directly to cookie cutter builds, where most of the choice is illusory, and you're only really distributing 2-3 points between situational/flavor talents.
With a sharp reduction in talents, Blizzard has a chance to make each tier an actual meaningful choice. Worst case, they won't be able to balance it out, and we'll be back to cookie cutter builds. But at least then there'll be fewer points to copy off Elitist Jerks.