Webgizmo may work now as well since it uses html 5 for playing multiple items if it's available. Can someone try it and report back?
Use the build from the top of this board.
I tried it last night. Version .119 I believe.
I was using Dolphin Browser HD.
I selected an audio smartlist, then clicked Play All. The first track appeared, then started playing when I clicked on it.
There were no controls visible, and the timer never moved even when the song was playing (see pic below).
After the song was finished, the next track never loaded.
Webgizmo didn't play at all using the stock Playbook browser.