I had a Lumia 800. There are quite a lot of important (to me) features that WP7 lacks, so I returned it and use my old Symbian based C7 as my main phone again meanwhile.

Will I buy a WP8 based Lumia? Depends on if these issues are resolved. I don't find any detailed information on WP8 so I cannot decide at the moment, but I'm relatively sure WP8 will not have the features I need. It's not that Microsoft couldn't implement them in WP7, they didn't want to because it's against their business model. So there's hardly any hope this will change in WP8.

So... no, probably no Lumia 920 for me.