Turbo was removed in the January 2012 patch. No, it will not be coming back.
I removed turbo for a number of reasons. First, in an attempt to lower abusers of pandora’s service, as the recent changes indicate they are paying further attention to third party clients. I don’t want to spoil being able to listen to pandora via a non-crap method. Maybe a vague hope they would not implement asinine changes like the sync keys.
Second, the server side skip error indicates increased attention to third party clients, and possibly the people who use them. I don’t want people coming to me complaining their x years old pandora account is now banned because they used my client and saw this nifty feature called turbo. Skip limit does not seem to be in effect for those using new sync keys (ie my client, and the pandora website), but they could change that any time, at which point I would remove turbo anyways as it was useless.
Basically, turbo was flagrantly abusive of the service Pandora provides. If you want to get large bunches of music, well, piratebay is that way.
Update, a few months later: Pandora has now taken measures to prevent turbo mode. So yeah, definitely not coming back.