I/ve not tried RC2 yet, but:
wxSmith, with a custom control the "Syle" property is not saved to the .wxs file.
I put a 0 in the field, but it is not saved, which gives build errors each time I re-open the project.
The following is missing <style>0</style> in my case
<object class="Custom" name="ID_CUSTOM1" subclass="wxGraph" variable="graph1" member="yes">
<creating_code>$(THIS) = new $(CLASS)($(PARENT),$(ID),$(POS),$(SIZE),$(STYLE),$(NAME));</creating_code>
<include_file>wxGraph.h</include_file>
<local_include>1</local_include>
<minsize>640,480</minsize>
</object>
which generates incorrect code, with a missing argument:
graph1 = new wxGraph(this,ID_CUSTOM1,wxDefaultPosition,wxDefaultSize,,_T("ID_CUSTOM1"));