All right, final info:
1st:
There's no possibility for an onboard visit. This is due to security issues.
[welcome in the 21st century

]
[I 1st contacted Cunard through the cunard.co.uk website: no answe within more than 3 days. Yesterday I contacted them through cunard.com ... reply within about 24 hours! (allthough negative)]
2nd:
Timing: (all estimated! - according to Port Authority today at 17.30)
3 am: "QE 2" at "Maasmond", the place (on sea) where the pilot will go on board.
4 am: "QE 2" entering the "Nieuwe Maas" at Hoek van Holland.
6.oo/6.30 am: "QE 2" at Cruise Terminal, downtown.
4 pm: departure from Cruise Terminal
6/7 pm: "QE 2" leaving the "Nieuwe Maas" seabound at Hoek van Holland
There's no evidence yet when and where the boat will be turned around. This could be allready in the morning (as they did with the "QM 2" two years ago, and also quite regulary with other cruiseships as ie. the "Golden Princess" which comes in quite regulary) or only when the "QE 2" will be leaving. To my experience the turn arounds take place in the "Waalhaven", some towing time downriver from the center. I'd guess that the preference is to turn around the ships allready in the morning ... as I'd judge the boats leaving the Cruise Terminal on it's own motors much more powerful and presenting more pride.
For those arriving last minute:
Nice viewing points along the route to the sea will be Rozenburg/Maassluis (south/north of the river), and finally Maasvlakte/Hoek.v.Holland (S/N).
And interesting side point:
Appearantly tomorrow afternoon around 5 pm at Hoek v. Holland the world's biggest/largest containership is to be expected: "Sin Los Angelos", of China Shipping Lines, coming in from sea. Could be a nice contrast meeting: "QE 2" and "SLA".
For departure viewing / pictures: remember that the sun will be shining from the west a around 6.20 pm local time. [5 degrees east of Greenwich]
Also remember to bring waterproof clothing. GoreTex or similar is the best choice as umbrellas tend to flip over in the windy conditions at and near the sea. Even GoreTex-trousers might be a good option.
eT