Improve multi language support
There are new ideas introduced in WPF with x:Uid in XAML and locbaml command line tool but the translation process is a mess, see http://wpflocalization.codeplex.com/
There should also be a standalone resource editor available for translators.
THIS, at so many levels.
Thomas Levesque commented
Yes, localization is definitely one of the things to improve... Why not take advantage of the existing ressource mechanism (.resx files) ? One can create its own localization framework using markup extensions or attached properties, but it would be better if there were standard built-in tools to do it...