The Hollywood Reporter reported the casting of Sean Astin as Sam Gamgee in THE LORD OF THE RINGS today, and in their complete article... They say...

"In an unusual move, New Line issued a statement saying it "recognizes the substantial media interest in the project and will assist journalists at the appropriate time. However, the studio will no longer comment on completed deals, current negotiations, rumors or speculation about any specific role." New Line says it expects to cast close to 100 roles in the trilogy and "will unveil the entire ensemble" when casting of the principals has concluded."

So, it seems that New Line is wanting to close down the rumor mill a bit at the moment, undoubtably because the leaking of cast members prior to final signing ends up costing New Line and the production in negotiations a tid bit here and there. Personally, I'm quite curious as to the rest of the cast... so I guess for a while here it'll be a bit before the rest of the cast comes out of the closet so to say.