I'm not impressed yet, and I know that better web experiences can be delivered.
However, now that I see this webplayer and recognize a few similarities with the desktop player, I can see why many of the horrifically terrible changes to the native player happened recently.
They were getting rid of native rendering and replacing it with rendering a webpage. No wonder people were so pissed and no wonder so much functionality was dropped.
EDIT: Okay, I'm going to say this. Webapps: USE MY RIGHT CLICK. You are NOT A WEBPAGE, so don't use a webpage right click!
Right click a song in native app: Play, Queue, Add To->Lists, Radio, Copy 3 Kinds of Links, Share, Delete from Playlist.
Right click on a song in web app: Back, Forward, Reload (breaks playback lol...), Save, Print, View Page Source, Reload Frame...
I love my right click menus and not having them in a webapp is very frustrating. Oh wait, this is supposed to also work for touch so I will never get a real alt-menu again, will I?