Before Windows 8 we just had years and years of incremental "sameness." Vista was meant to be a big shake-up but instead that got shelved and we got a very modest improvement over XP (driver issues and memory consumption not withstanding), the same with 7, it was a very incremental improvement over Vista (even if coming from XP directly made it look bigger).
Windows 8 was where the company decided to really try something new. It was the largest UI shakeup since Windows 95/NT 4.0. And I think that shakeup helped shake some cobwebs loose because since then Microsoft are continuing to take bigger (welcome) risks.
Even just looking at the Windows 10 technical preview feedback program should tell you this is a new Microsoft. In previous Windows pre-releases, they would fix bugs in alpha/beta releases, but never made UI or functionality changes just based on feedback. They ARE with Windows 10.
If you go look at the feedback Windows 10 has received, several major pieces have been actioned.
Seems like the company has a fire lit under it again. It is welcome.