In response to a user question when Qt 5.0 Beta will be released, Lars Knoll, the long-time Qt developer, responded: "Yes, some things have been a bit more difficult lately, so it takes longer than I had hoped for. Things are getting closer to a release, but current circumstances make it a lot harder to give an exact day. But I hope it won't be for too long anymore."
Among the recent changes have been Nokia getting rid of their Qt Australia office and Nokia subsequently selling Qt to Digia. The sale and canning of some of the Qt developers has already harmed the Qt 5.0 release and Lars Knoll already said it's really sad to see this happen.
With the beta being slow to come, it's likely the final release will be pushed back as well. After already facing delays, the final release of the Qt 5.0 tool-kit was supposed to come in mid-to-late August. The current Wiki information cites Qt 5.0 final for September, but that's highly unlikely based upon the recent changes.