Hello Juan Pablo,
Thank you for contacting us.
I am happy to share with you that there will be a new Telerik Message Box in our next release - Q3 2008 - that will use Telerik themes. The new control will be available early next month.
For more information, please review the roadmap: http://www.telerik.com/products/winforms/roadmap.aspx
All the best,
the Telerik team
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