As Jorus said. We ran the ROM numbers (well we're probably within a few orders of magnitude) and the falling debris will cause huge damage to the equatorial regions. It'll do significant damage to infrastructure and lead to loss of life.
[member="Atretes Rhoujen"] stated on Page 16 that they were adding some spin to the station, so we can assume quite a bit of it will have a larger |v| as it hits atmo, with much burning up or bouncing off. However, it would probably take hours and hours at least to give it enough spin to send chunks away from the planet (given that in early posts bits started falling - in hindsight it would have been easier to make the initial assumption that it had enough spin to simply break apart safely)
The only long term effects will be from the reactors that are going to come down, which we can safely assume will be mildly explosive after what happened to the death stars....
So lots of nukes landing on cities, but not earthquakes, mountains or extinction level events.