Can Symbian 7.0 runs Symbian 6.0 apps without modifications?

No. Versions 6.x and 7.0 of Symbian OS aren't entirely compatible. In any case, the P800 (currently the only v7 Symbian device) has a different user interface and screen size to the Nokia 9210 and 7650.

Yes, you will be able to run a Series 60 application compiled for Symian OS 6.1 on a device running Series 60 for Symian OS 7.0, when it becomes available. But you can of course not run a Series 60 application on a P800 (or vice versa) regardless of the version.

I think as the previous post explains it would be possible but not all the way.

The Series60 is the UI developed by Nokia over symbian 6.1 OS (Also called Avkon for nokia developers). The UI for the P800 is different, and so is the OS (Symbian 7.0). Hence Series60 APP will not run on the P800 (obviously 😉 ), but I wonder about true Eikon apps ??

Also if an OS update is available somewhere down the line for a Series60 running on Symbina 7.0 then it should be able to run these things..

But my take on the whole issue, I dont think it is going to happen... 😞