Microsoft is taking the Lumia Camera code as the base for the new camera app, including its faster load times, and putting it right into Windows 10. This means that HTC and Samsung devices will soon get those cool manual controls, and new simpler UI found in Lumia Camera 5.0. It should be a part of the upcoming preview next month.
This news also means that Windows 10 tablets and PCs can use the same app, of course.
For those with a Lumia, do not fret. There are still hardware differences that will limit some features like 4K videos, and Microsoft does plan to keep at least some things Lumia-exclusive for now e.g. Living Images and Rich Capture. That tech may eventually trickle down into the main Windows 10 codebase as hardware evolves, but for now, Microsoft will give their PureView Lumias a little extra power.
Finally, there was one big change to the demo we saw tonight. Previously, when you tapped the little photo icon in the upper left corner, it launched into a photo history instead of the formal Photos app on Windows Phone. In Windows 10, this changes. Now, that button takes you into the newly announced Photos app experience directly. It's a small but smart change.