Adding a localization extension, and making the directionality for tinymce be based on if the content has a ILocalizationAspect or not. Doing this ensures that you are not affected by the current culture of your site. If you do not has a ILocalizationAspect, then reason dictates that you should always use the site culture, not the current culture and new items are created using the site culture not the current culture.

src/Orchard.Web/Modules/TinyMce/Views/Body-Html.Editor.cshtml

@@ -1,15 +1,15 @@
-@using System.Globalization
+@using Orchard.ContentManagement
 @using Orchard.Environment.Descriptor.Models
+@using Orchard.Localization
 
 @{
     var shellDescriptor = WorkContext.Resolve<ShellDescriptor>();
-    var currentCulture = CultureInfo.GetCultureInfo(WorkContext.CurrentCulture);
 }
 
 <script type="text/javascript">
     var mediaPickerEnabled = @(shellDescriptor.Features.Any(x => x.Name == "Orchard.MediaPicker") ? "true" : "false");
     var mediaLibraryEnabled = @(shellDescriptor.Features.Any(x => x.Name == "Orchard.MediaLibrary") ? "true" : "false");
-    var directionality = '@(currentCulture.TextInfo.IsRightToLeft ? "rtl" : "ltr")';
+    var directionality = '@Html.Directionality((IContent)Model.ContentItem)';
 </script>
 
 @{ 

src/Orchard/ContentManagement/ContentExtensions.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using NHibernate.Criterion;
 using Orchard.ContentManagement.Records;
 
 namespace Orchard.ContentManagement {

src/Orchard/Localization/HtmlLocalizationExtensions.cs

@@ -0,0 +1,26 @@
+using System.Globalization;
+using System.Web.Mvc;
+using Orchard.ContentManagement;
+using Orchard.ContentManagement.Aspects;
+using Orchard.Mvc.Html;
+
+namespace Orchard.Localization {
+    public static class HtmlLocalizationExtensions {
+        /// <summary>
+        /// The dir attribute specifies the text direction of the element's content.
+        /// 
+        /// Returns rtl or ltr based on if your content has an ILocalizableAspect or not.
+        /// </summary>
+        /// <returns>Returns rtl or ltr</returns>
+        public static string Directionality(this HtmlHelper html, IContent content) {
+            var workContext = html.GetWorkContext();
+
+            var culture = workContext.CurrentSite.SiteCulture;
+            if (content.Has<ILocalizableAspect>()) {
+                culture = content.As<ILocalizableAspect>().Culture;
+            }
+
+            return CultureInfo.GetCultureInfo(culture).TextInfo.IsRightToLeft ? "rtl" : "ltr";
+        }
+    }
+}

src/Orchard/Localization/Text.cs

@@ -1,7 +1,5 @@
 using System;
 using System.Globalization;
-using System.Linq;
-using System.Web;
 using Orchard.Localization.Services;
 using Orchard.Logging;
 

src/Orchard/Orchard.Framework.csproj

@@ -261,6 +261,7 @@
     <Compile Include="FileSystems\Media\FileSystemStorageProvider.cs" />
     <Compile Include="FileSystems\Media\IMimeTypeProvider.cs" />
     <Compile Include="Indexing\ISearchBits.cs" />
+    <Compile Include="Localization\HtmlLocalizationExtensions.cs" />
     <Compile Include="Localization\Models\DateLocalizationOptions.cs" />
     <Compile Include="Localization\Models\DateParts.cs" />
     <Compile Include="Localization\Models\DateTimeParts.cs" />