Precisely what's in that package remains a mystery we'll solve later today. But last week, Udall emphasized three key changes: a ban on secret holds; a ban on filibustering the start of debate (thereby limiting the filibuster to ending debate on legislation, nominations, etc.); and a more intricate requirement that the minority actually hold the floor during a regular filibuster.
This process of amending and adopting the rules traditionally kicks off on the first day of a new Congress, but with the help of a calendar trick it can actually last multiple days, and is expected to extend the "first day" of the 112th until the end of January.
This is the "constitutional option" track. Running parallel to it are negotiations between Democratic and Republican leaders who could introduce a more modest package of rules changes and supplant Udall's effort. Importantly, those negotiations would be fruitless without a credible threat from Udall and his allies of imposing a deeper package of reforms.
Thus, in all likelihood, we won't know how this plays out for at least a couple weeks. But that was all baked into the cake.