Will definitely be interesting when WP8 hits.
I'm more interested in Nokia mainly because of build quality.
My friend has a Lumia 900 and the amount of abuse that phone has taken is absolutely insane to say the least. I've personally seen it be dropped 5+ times and nothing has happened to it. It has probably been dropped way more than that.
I think the new Lumia models will both get a 0.3'' increase in screen size so hopefully we will se a 4.6'' Lumia 900(920?)