It is really out-of-place, compared to other desktop applications, and annoying.
The consensus of the desktop team is that we would be better off without it.
Luckily, Ubuntu already has a patch for this:


--- gimp-2.3.18.orig/debian/patches/10_dont_show_wizard.patch
+++ gimp-2.3.18/debian/patches/10_dont_show_wizard.patch
@@ -0,0 +1,32 @@
+diff -Nur gimp-2.3.16/app/dialogs/user-install-dialog.c
gimp-2.3.16.new/app/dialogs/user-install-dialog.c
+--- gimp-2.3.16/app/dialogs/user-install-dialog.c	2007-01-23 11:13:50.000000000
+0100
++++ gimp-2.3.16.new/app/dialogs/user-install-dialog.c	2007-05-02
17:54:23.000000000 +0200
+@@ -46,15 +46,18 @@
+ gboolean
+ user_install_dialog_run (GimpUserInstall *install)
+ {
++#if USER_INSTALLATION_DIALOG
+   GtkWidget *dialog;
++#endif
+   gboolean   success;
+ 
+   g_return_val_if_fail (install != NULL, FALSE);
+-
++#if USER_INSTALLATION_DIALOG
+   dialog = user_install_dialog_new (install);
+-
++#endif
+   success = gimp_user_install_run (install);
+ 
++#if USER_INSTALLATION_DIALOG
+   if (! success)
+     {
+       g_signal_connect (dialog, "response",
+@@ -67,6 +70,7 @@
+     }
+ 
+   gtk_widget_destroy (dialog);
++#endif
+ 
+   return success;
+ }

If we apply this, we should also lobby upstream to nuke the wizard, or at
least make it a compile-time option.