I think the most kickass feature any IDE could have would be wizard that does "analyze code in these assemblies and change the IDE's code style settings to match it".
For every style option, if there's not a 90% (customizable) consensus in the code, it should ask how to resolve every ambiguity.
Then finally the wizard should ask me if I want to format the rest of the code with these rules and fix inconsistencies.
Probably very hard to implement tho :)