This is greatly helpful for important news, announcements, and the like without having to create a Portal page (for those that don't use it) specifically to include that information. Once the Force Read is in-place, users couldn't do anything until they clicked the button to take them to the thread.
However, I wish that it would be taken a step farther than just a force read thread, I would it to include Conversations as well.
On our forum, we do get people who are a bit unruly on the forum and sometimes we send them a PM concerning about it. Not all read the PMs (there is a "Read Receipt" put on all PMs that concern official forum business), so this would be very handy to have.
Only thing I would like to see done different, besides adding Conversations to the list, would be instead of just going by usergroup, it could also to specific members. For example, I want JimBob, DuglyDoright, DeXtEr87 and Marco-Polo (who all are registered members) specifically to be forced to read the rules of the site, but I don't want all registered members to be forced to reread it. Or maybe I want all Graphic Team group, JimBob and DeXtEr87 to read it a specific thread about some sort of news.
I hope I made this clear enough lol