I just installed Xcode 4 and the opening brace of the auto generated functions is on a new line.
For example :
- (void)dealloc { [_window release]; [
All the template code that XCode 4 uses to create new class files is in /Developer/Library/Xcode/Templates/File\ Templates/Cocoa/Objective-C\ class.xctemplate
Just edit those templates to suit your coding style and you are good to go.