On page 26 of the rulebook, each of the three scenarios in the core set has a number indicating its difficulty level. There's no mention of what the upper or lower limit on difficulty is. Regardless, I'm excited to find out the level of difficulty of the new quest in Hunt for Gollum.
While I'm waiting for June, I thought I'd ask the nice folks here: knowing that Mirkwood is a 1, Anduin is a 4, and Dol Guldur is a 7, what Difficulty Level would you like Hunt for Gollum to be? If you don't want to pick a number, you can always give a preferred rank in relation to the existing quests.
Special secret bonus question: if you'd like, you can also predict where it will actually be ranked.