That's funny. I thought the whole 0.43 thing was about putting the tcl/tk into one place. In 0.42 the tcl/tk (one of the slowest languages around) is all over the Pd code, not just in pd.tk.
Martin
I guess drawing/erase commands are all over pd's code but this is easily identified and replaced with appropriate draw/select/unselect/delete commands, hence personally I don't feel this will be an issue. What will be a much greater issue is porting all the custom externals from other libs to be supported under the new toolkit (whatever that may be).