It's good to see some wxMac changes again. Work has been made towards a native toolbar using wxMac, here's a screenshot:

For those of you not familiar with Mac OS X toolbars, the little button on the upper-right of the window allows you to show and hide the toolbar. Pretty cool! Another step in perfecting BitWise on all platforms.
Unfortunately, there's no support yet for embedded controls so the whiteboard toolbar is missing the spinner for the line width. That should come sooner or later. :)