# Форма первого шага
class W1_ParamForm(forms.Form):
	cities = forms.ModelChoiceField( label = 'Город', empty_label=None, 
		initial = '1', 
		queryset=City.objects.all().order_by('name') )

#Форма второго шага
class W1_SelectForm(forms.Form):
	oEstates = MyModelMultipleChoiceField( 
		queryset = RealEstate.objects.
			filter(city_id__exact = ...).
			order_by('priceM'),
		widget = forms.CheckboxSelectMultiple,
		required = False)

# Это вью
class W1_Estim(SessionWizardView):
	template_name = "w1_estim.html"

	def done(self, form_list, **kwargs):
		form_data = [form.cleaned_data for form in form_list]		
		return render_to_response('w1_done.html', {'form_data': form_data})

urlpatterns = [
 ...
# Это запуск мастера
   url(r'^doestim$', W1_Estim.as_view([W1_ParamForm,W1_SelectForm]), name='doestim'),
 ...

def get_form_initial(self, step):
   if step == '1': 
      # on SECOND step get data of first step
      step0data = self.storage.get_step_data('0')
      if step0data:
         cities = step0data.get('cities', '')
         return self.initial_dict.get(step, {'cities': cities})
   return self.initial_dict.get(step, {})

def __init__(self, *args, **kwargs):
   c = kwargs['initial']['cities']
   self.oEstates = ModelMultipleChoiceField( 
      queryset = RealEstate.objects.
      filter(city_id = c).
      order_by('priceM'),
      widget = forms.CheckboxSelectMultiple,
      required = False)
   # поле oEstates НЕОБХОДИМО включить в "declared_fields"!!!
   self.declared_fields['oEstates']=self.oEstates
   # конструктор суперкласса следует вызвать ПОСЛЕ включения поля в "declared_fields" !!!
   super(W1_SelectForm, self).__init__(*args, **kwargs)