From the outside, it seems like he's made a lot of positive changes. Windows is no longer the sacred cow it used to be, the company is showing some cutting-edge products like HoloLens (an augmented reality headset), and he's been much better than his predecessor Steve Ballmer about stating a clear vision for the company's future.
But what about inside the company?
We've been polling Microsoft employees for the last week, and it turns out they're just as excited about Nadella as the outside world is.
These employees were not authorized to talk to the press on this topic, so we are protecting their confidentiality. But here are some common themes that came up:
They're delighted about the end of Windows-first. Every person we spoke to praised the end of the old "Windows-first" culture.
One person who worked closely with the team that built Office for iPad said the apps were done for about a year before their release, but Ballmer wanted to sit on them until a touch-first version for Windows was ready to roll, which probably won't happen until later in 2015. The team was demoralized, and Nadella's decision to change courses and release Office for iPad last year - which brought Microsoft a lot of positive acclaim - was a morale booster.
Another person said that Nadella has basically given employees "permission" to do what they already knew they needed to do in order to boost Microsoft's fortunes on non-Windows platforms, such as acquiring iOS apps like Accompli and Sunrise.
A third employee told us that people walk around more freely with iPhones and Android phones now. It's not as if there was a "culture of fear," under Ballmer, but Ballmer did perform stunts like pretending to stamp on an employee's iPhone at the company meeting, so some folks felt a little shy about using non-Microsoft technology on campus. That's gone now.
It's exciting to work at Microsoft again. Another thing that almost everybody mentioned: It's a lot more exciting to work at Microsoft now that Nadella is in charge.
One engineer told us that it could be frustrating to have all these brilliant people working at Microsoft, then see their work slammed in the press because Microsoft was considered to be old and out of touch. But thanks to surprises like Office for iPad and the HoloLens, the press is starting to pay positive attention again. This person also told us that Nadella is a lot more transparent and open than Ballmer was, and so people feel freer to try new things.
People used words like "dynamic" and "thrilled" to describe the culture. One 15-year-veteran said he has a lot more "faith" in where Microsoft is going now than he did a year ago.
But there's hard work ahead. A couple people acknowledged that Nadella couldn't possibly change everything that was broken with Microsoft in one year.
For instance, Microsoft's last earnings report showed slowing growth in its core business: selling software and services to big enterprises. One person thought there might be some more slow quarters ahead, but believes the company's finances will start cranking again after Windows 10 and the next wave of Office and related products are out.
Another person noted that the layoffs are not quite over yet, but said they didn't affect that many people in Microsoft's main campus in Redmond, Washington, and the people who were cut mostly found jobs in other divisions (most of the laid off employees came from Nokia, the phone company Microsoft acquired in 2013). It sounds like this layoff was a lot less disruptive than the layoffs during the recession in 2008-09.
The only bad thing they mentioned? A couple people mentioned Nadella's slip-up at the Grace Hopper conference, where he said that women shouldn't necessarily ask for a raise, but do a good job and trust karma. But both of these people were happy how quickly and completely he apologized - a kind of humility that Nadella's CEO predecessors seldom showed.
So the honeymoon for Nadella may be ending on Wall Street, but he's still got a lot of runway inside the company.