The last, and most complete, version of Windows Media Center sported a clean interface familiar to Windows Phone users
Windows Phone? You probably mean Windows Mobile. Windows Phone 7 and beyond were TIFKAM (even if it wasn't even called Metro yet) ... Probably the only design element that reminds one of actual Windows Phone was the large, lowercase titles stacked next to each other (like the example contact details page in the second screenshot in this picture)
The rest of the interface was beautifully Windows Pre-TIFKAM, mostly Windows 7 and Windows Mobile 6.5.*
As a side note, I used to LOVE Windows Media Center (and Windows Mobile). Just beautiful, just simple. Although not 100% aesthetically or functionally perfect, it's not the mess that's in a modern TV-connected gadget, Apple TV included.
(Of course, just like most forms of art, it's quite functionally crippled).
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* Of course I'm referring to the Windows 7 implementation, not the XP one. The latter was ugly. Damned ugly.