I wasn't trying to imply cb should abandon (wx)scintilla, rather that the cb base should be flexible enough to accomodate more than one source editor control. the news about wxscintilla just highlights the risk of being unnecessarily tethered to upstream projects.
wrt gtksourceview, it would be a natural fit on linux. wxwidgets on linux is wxgtk after all. if it was a plugin, would it matter if it wasn't multi-platform? (still have scintilla). gtksourceview might not be better than scintilla, just an alternative (and who knows what the future may bring).