Lombi:
page changing without reloading and it's effects on the publishers that are funded by PPC companies like google/yahoo/adbrite/whatever
This means that you will have to put your PPC ads into page bodies rather than header/footer on AJAX websites.
Dayver:
If I understood it to perform this function in Seditio-N plans to implement the switch that will be available to visitors to the site (more so is it for him) to switch between AJAX / "traditional full path"? Or, this switch will be automatic that reacts to the "inclusion" JavaScript on the client side (and/or the fact whether the visitor search bot)?
I think the switch should be automatic
Yes, it will be automatic. Crawlers and other javascript-less machines won't even know that the site can act in AJAX mode. And as for browsers, AJAX mode will be enabled only if available.