Qt provides right now QThread as a way of managing threads in a platform-independent manner, there's various other Qt classes for dealing with threading, and there's also various other patches under review for enhancing Qt's multi-threading abilities. However, Qt developers remain split on the best way for handling multi-threading.
Sze Howe Koh started a new thread on the Qt developers' mailing list about evolving the Qt multi-threading API to hopefully incorporate the requests of all developers.
Among the items that have been talked about is re-doing the QtConcurrent class, finding a third-party solution for high-level multi-threading, and influencing C++1y by creating a nice multi-threading API for the language.
Some suggestions have also included putting a Qt wrapper around Intel's Threaded Building Blocks (TBB) and integrating ThreadWeaver back into Qt. One of the recent messages on the mailing list was also on leveraging OpenMP for multi-threading.
So far nothing conclusive has come out of these Qt multi-threading discussions beyond acknowledgement by developers that the tool-kit's support can/should be revamped. This is obviously too late to happen for Qt 5.1 but hopefully a course of action will be decided upon in the near future.