That's exactly what I thought when I saw them. Especially since in the RoC cinematic, he holds up the crown like that. (well... not exactly... but y'know)
This was actually a 3D model or something made by someone for the blizz art contest or something like that... I think.
Those rose petals are indeed the ones from RoC. They are known as "Arthas' Tears" in WoW, which were thrown down upon Arthas cheerfully as he walked down across the path to King Terenas' Throneroom. In WoW, if you look closely and zoom in, you can still see the pedals on the ground over the path he walked in Undercity.
It never fails that as soon as I say something about the bots they come back - this time they are under a whole new IP range - one thing in common though, Chinese!
I am working on getting access to the old news portal under a different URL for those that would rather use that for news before we get a different news view.