The Outlook2007 skin is available only for the classic RadGrid for ASP.NET and I am afraid we don't intend to make it a common skin for all controls, because we have the Office2007 skin, which looks almost the same. Fortunately, the Office2007 skin has a small font size (other skins with small font size and compact layout are Outlook, WebBlue, Vista and Default2006, which we finally decided not to remove from the assembly).
However, we will keep you request in mind when planning and designing new skins. Thank you.
the Telerik team