Jukebox mode in Rock Band 3 with Party Shuffle?
One solution I've seen -- and it is very, very ghetto -- is to get an auto-turbo controller and enable "turbo fire" on the A button (for example, on XBox, or whatever the equivalent is on PS3).
This effectively causes the game to advance past the song results screen to the next song.
Not pretty, and I don't really want to buy a whole controller for this, but it might be the only thing that works.
I finally got around to buying a turbo controller to see if this works. I chose the Horipad EX2 Turbo. $25.72 at the time of writing from Amazon, and wired only, but that doesn't matter too much -- and is arguably better for this use case, since who wants to replace batteries on a controller that's turbo-ing and constantly mashing buttons all the time?
To get it to work:
hold the special turbo button at the top of the controller
press the regular controller button I want to make turbo, A
press the A button again to make it 'auto' turbo
The green turbo LED flashes constantly when you do this, I guess to indicate that it's mashing the A button every time that LED flashes. But.. it works! I can do "party shuffle" and it moves from song to song with no effort on my part. Awesome!