When changing culture, you might be changing diretionality, it would be worth changing that on the fly, though a page reload might be better.

src/Orchard.Web/Modules/Orchard.Localization/Views/Admin/Translate.cshtml

@@ -15,6 +15,8 @@
 <script type="text/javascript">
 //<![CDATA[
     (function ($) {
+        "use strict";
+
         // grab the slug input
         var slug = $("#Autoroute_CurrentUrl");
         if (slug) {
@@ -31,6 +33,21 @@
                 }
             });
         }
+
+        var culture = $("#SelectedCulture");
+        culture.change(function () {
+            var optionDirectionality = $("option:selected", this).attr("data-content-dir");
+            var contentZone = $(".zone-content");
+            if (contentZone.hasClass(optionDirectionality))
+                return;
+
+            var oldClass = optionDirectionality === "ltr" ? "rtl" : "";
+
+            contentZone.removeClass("content-" + oldClass);
+            contentZone.addClass("content-" + optionDirectionality);
+
+            $.trigger("localization.ui.directionalitychanged");
+        });
     })(jQuery);
 //]]>
 </script>

src/Orchard.Web/Modules/Orchard.Localization/Views/CultureSelection.cshtml

@@ -1,4 +1,6 @@
-@model Orchard.Localization.ViewModels.AddLocalizationViewModel
+@using System.Globalization
+@using System.Text
+@model Orchard.Localization.ViewModels.AddLocalizationViewModel
 @{
     Style.Require("LocalizationAdmin");
 }
@@ -6,7 +8,25 @@
     <label for="SelectedCulture">@T("Content Localization")</label>
     <div>
         @T("This is the <em>{0}</em> variation of {1}",
-        Html.DropDownList("SelectedCulture", new SelectList(Model.MissingCultures, Model.SelectedCulture)),
-        Html.ItemEditLink(Model.Content))
+            BuildSelectedCultureList("SelectedCulture", Model.MissingCultures, Model.SelectedCulture),
+            
+            Html.ItemEditLink(Model.Content))
     </div>
-</fieldset>
+</fieldset>
+@functions{
+    private string BuildSelectedCultureList(string name, IEnumerable<string> siteCultures, string culture) {
+        TagBuilder selectTag = new TagBuilder("select");
+        selectTag.Attributes["id"] = name;
+        selectTag.Attributes["name"] = name;
+
+        foreach (var siteCulture in siteCultures) {
+            TagBuilder optionTag = new TagBuilder("option");
+            optionTag.Attributes["data-content-dir"] = CultureInfo.GetCultureInfo(siteCulture).TextInfo.IsRightToLeft ? "rtl" : "ltr";
+            optionTag.Attributes["value"] = siteCulture;
+            optionTag.SetInnerText(siteCulture);
+            selectTag.InnerHtml += optionTag.ToString();
+        }
+        
+        return selectTag.ToString();
+    }
+}

src/Orchard.Web/Modules/Orchard.Localization/Views/EditorTemplates/Parts/Localization.ContentTranslations.Edit.cshtml

@@ -39,4 +39,4 @@
     @if (Model.SelectedCulture != null && !siteCultures.All(c => c == Model.SelectedCulture || Model.ContentLocalizations.Localizations.Any(l => c == l.Culture.Culture))) {
         <div class="add-localization">@Html.ActionLink(T("+ New translation").Text, "Translate", "Admin", new { area = "Orchard.Localization", id = Model.ContentItem.Id }, null)</div>
     }
-</fieldset>
+</fieldset>