The last time they introduced a new major version (5.5 -> 6.0) , they had a special deal on upgrading OEM
to full versions of 5.5. So effectively, you got both a full 5.5 and 6.0 serial number for the one price. I don't know if that'll happen this time, but it's worth watching for.
As to what's coming, heise
had a bit more information. New versions of Nero Vision, Nero Wave Editor, Sound Trax, Backitup and InCD are coming. Nero SoundBox will mix 5.1 or 7.1 sound. Nero 7 itself will handle BluRay and HD-DVD (as expected) and InCd will support the appropriate UDF version (2.5/2.6)
The major innovation is apparently a revamped "Media Home" with Media center look.
Personally, there's nothing there that I need at this moment- I'll wait until it ripens a bit. I just hope the bug fixes keep coming for Nero 6.