Argh! I just updated to iOS 5 and had I known about the changes in the music player, I wouldn't have done it!
It severely hampers my use of it, mainly for podcast listening:
missing top level list view
the track list view is too small and lacks dates
podcasts are now relegated into the "more" submenu
no more "x2" double speed playing
And, just for completeness, what has been always missing is a volume boost with the equalizer (as in Mac iTunes), necessary for some podcasts recorded with too low levels.
And what are these silly wood imitation sidebars there for? They're ugly, and I'd rather display more information.