No, it's not a joke. Press release: http://www.dpreview.com/news/1009/10091509sb700.asp
What I consider to be major upgrades from the SB-600:
Commander capable (up to 2 groups). Now there are four commander options for Nikon (in addition to the popup flash): SB-700, SB-800, SB-900 and SU-800.
Head rotation: 180 degrees to both sides according to Nikon.
Zoom coverage up to 120mm.
SU-4 optical slave mode. See here.
Other features similar to the SB-900 such as the interface, light distribution pattern, support for gels, overheat protection, etc.
What I consider to be notable missing features:
Power - the press release gives a GN of 38m at 120mm zoom, 100 ISO. I'm guessing the 35mm zoom is 1 stop weaker, meaning about 27m, which is a bit weaker than Nikon's stated GN for the SB-600 (30m at 35mm zoom, 100 ISO). The cynic in me thinks this is intentional on Nikon's part to force us to buy more. :)
Not unexpectedly, the price is much higher than that of the SB-600, at $329.95. I guess this is a viable alternative for those who were disappointed with the discontinuation of the SB-800. Fortunately, the SB-600 is still listed on Nikon's website (for now) as a more affordable (and possibly more powerful) alternative.