While it's easy to declare 2.7 a grand success, it's greatness is defined mostly by the weakness of 2.5. It is to me symptom of a long and ongoing issue with how WP gets developed.

2.5 was the "we know better" update. It put something in place that, while seemingly good, was in fact a real negative for many. The tools were okay, but the design and layout wasn't what people expected or particularly wanted.

Consulting with the end users (via survey) gave you enough data to make a pretty solid leap forward, one which is effectively still in use today. That came from listening those people who use the tools, and not those who design them.

The ongoing issue is one of "we know better". Every so often WP take a solid left or right turn, often out of the blue, and seems to have left the public out of the process. It takes time for those things to get resolved and healed, usually a couple of versions later.

The relative failure of 2.5 and the success of 2.7 should be food for thought every day, and something designers and programmers should always consider before just adding in the latest thing.