http://www.themeparkinsider.com/flume/201003/1818/
The link above gives a little more detail into what the Forbidden Journey will be about. It gives the same YouTube video on the scenes the actors are filming for the ride, but talks about how this is possibly an hour long ride from start to finish as it begins when you first enter Hogwarts.
This won't affect our trip, specifically, but might affect some of yours. Just an observation I have made regarding early park entry hours and Express at WWoHP.
When I pull up my current reservation for a single night at HRH, the details on early park admission are as follows:
Early Park Admission to Islands of Adventure
Traveling now 6/17/10:
Receive Early Park admission* to Universal's Islands of Adventure. The theme park will open thirty (30) minutes early each day so you can enjoy The Amazing Adventure of Spider-man® and The Incredible Hulk Coaster® before the rest of the general public!
Traveling 6/18 12/31/10:
Enjoy Early Park Admission one (1) hour prior to Universals Islands of Adventure regular scheduled park opening. Offer valid 7 days a week for travel; valid at Harry Potter and the Forbidden JourneyTM, Flight of the HippogriffTM, Dragon ChallengeTM and The Cat in the HatTM.
*Requires theme park admission. Offer valid 7 days a week for travel from 1/1/10 to 12/31/10. Only valid for Universal Parks & Resorts Vacations guests who purchase a complete vacation including hotel and theme park tickets. If technical problems arise or the opening of an attraction is delayed another Universals Islands of Adventure attraction will open for Early Park Admission. Offer subject to change at anytime without notice.
Note that at the time I booked the stay, the dates were "now -5/27/10" and "5/28 -12/31/10". So this has been changed (as they warn above, "without notice.")
As for Universal Express Ride Access, all it says is "Some attractions excluded." Based on the information in the link above, "The queue will be part of the attraction (and so, no Universal Express access, at least initially) and begin the dungeons of the castle. "
So it looks like you won't be able to Express this ride (and maybe you wouldn't want to, since so much of the attraction appears to be in the queue).
My point is, people who might have booked a stay at one of the Universal on-site hotels without the package, may not be allowed to ride the Forbidden Journey if their stay is between 5/28 and 6/17, although they thought they could when they booked their trip.
Since Universal apparently says that they will honor the packages for the dates 5/28 and after, I would hope that they would also honor the early entry privilege for on-site guests (as originally marketed) as well.