A few days ago Tyler posted some pictures of the "auto-gen"* for X-Plane 10's global scenery.
First, a few notes on hardware and performance: Propsman took these pictures on a new iMac, so that's a core i5 and a Radeon HD 5000 series GPU - that is, a pretty decent system. Hardware technology continues to advance rapidly (especially on the GPU front), so there's a big difference between a 'decent' system bought today and even a hard core system from two years ago.
I don't know what your performance will be like. I do know that the system is performing well enough so far in its not-really-all-that-optimized form that we think we can ship it, and more importantly I know that we can turn the level of detail down in a number of ways to lighten the load as needed.
The most expensive feature you see here is the real-time 3-d global shadows. Heavy shadowing combined with heavy 3-d does add up and hit the system hard, but I think we'll be able to have intermediate shadow settings that should be more affordable.
X-Plane 10 will use hardware instancing if your GPU is capable of it, and it makes a big difference in the amount of 3-d you can show.
X-Plane 10 is also quite a bit more fill-rate intensive than X-Plane 9; if your GPU is having fill-rate problems with version 9, some version 10 features will be out of reach. In the past, X-Plane has been light on fill-rate, so we've had users running with cut down cards (like a GeForce 8400) without realizing that their card isn't that fast.
Some users have asked about architecture and localization. I expect we will not ship out of the box with multiple local regions; however, the library system allows us (or any third party) to provide new artwork sets for local, architecturally reasonable buildings.
Finally, it might be a bit difficult to see in these pictures (because they are focused in on the detail), but the 3-d buildings you see here work with the real-world roads. In the past, we've had a clash between the buildings and roads vs. the terrain texture. This is a problem we are solving for X-Plane 10.
* Auto-gen, meaning bulk buildings that populate the world in urban areas...whether it's really auto or gen or anything like autogen in the past is a complex discussion that will have to wait.