Maybe not a bug in the direct sense, but definitely a cause for mistakes and confusion:

Code:
Ext.create('my.Class', { someConfig: true});
Ext.ModelManger.create({someField: 'value'}, 'my.Model');
To create an instance of a class, first the name of the class is supplied and then a config object (object initializer). To create an instance of a model, an initializer object is required, then the name of the model.

I think this is inconsistent.