go=lrb for left, right, and bottom scrollbars respectively.

vimperator/NEWS

@@ -1,5 +1,7 @@
 2008-XX-XX:
     * version 2.0 (probably)
+    * IMPORTANT: For compatibility with vim, guioptions=b has been renamed
+      'B'. 'b' now represents the bottom scrollbar.
     * IMPORTANT: :set now sets multiple options, as in Vim. Spaces in values
       must be quoted or escaped.
     * IMPORTANT: Due to much improved autocompletion, changed default 'complete' option

vimperator/content/config.js

@@ -33,12 +33,12 @@ const config = { //{{{
 
     /*** optional options, there are checked for existance and a fallback provided  ***/
     features: ["bookmarks", "hints", "history", "marks", "quickmarks", "session", "tabs", "windows"],
-    defaults: { guioptions: "r" },
+    defaults: { guioptions: "rb" },
 
     guioptions: {
         m: ["Menubar",      ["toolbar-menubar"]],
         T: ["Toolbar",      ["nav-bar"]],
-        b: ["Bookmark bar", ["PersonalToolbar"]]
+        B: ["Bookmark bar", ["PersonalToolbar"]]
     },
 
     get visualbellWindow() getBrowser().mPanelContainer,