I downloaded a few trailers yesterday. I think the shop is as bad as what I used on the Wii or 3DS. No background downloading, no queuing multiple downloads, they come in packages for some reason, no indicator of download speed/time/etc, and after a download finishes it bumps you back to the home screen (instead of the e3 video page).
That said, trailers reminded me of how neat and how useless 3D is. Kid Icarus looked great and I dug that aiming reticule is in 3D space; you don't notice this at all in the 2D trailers and it reminds me of Oni. Zelda uses the 3D really well...kinda surprising. I might actually play some portions in 3D. Paper Mario and Resident Evil use 3D well too. But Mario, Mario Kart and Star Fox are all bad; I could barely notice the effect in those trailers. Odd since Mario was supposed to take advantage of 3D and it was the least impressive.