Most prominent is the investigation into the shootings at Fort Hood this fall, and Lieberman is holding an 11:30 press conference at the Capitol on the issue after meeting with Defense Department officials.
He has been closely coordinating with the Obama administration on documents and witnesses who will testify at the Fort Hood hearings, sources tell us.
Also of note, Lieberman is about to pass out of his committee a major domestic partners bill extending benefits to same-sex partners of federal employees. It goes much further than Obama's executive order was able to, filling in the gaps and offering more benefits to more people.
The partner legislation in the House is unlikely to reach the floor any time soon, however.
He's also working on biosecurity measures to protect labs that make pathogens that could be used in weapons of mass destruction.
Lieberman was allowed to keep this leadership post in part because President Obama and former Sen. Ken Salazar, now an Obama Cabinet member, argued he should remain in the Democratic caucus despite campaigning for the Republican presidential ticket.
The administration has been open about his role in the climate bill as Lieberman, Sen. John Kerry (D-MA) and Sen. Lindsey Graham (R-SC) are huddling five times a week on the legislation that will ultimately hit the Senate floor.
A Congressional source described Lieberman as "incredibly engaged" on the issue, and said his position is even arguably "progressive."
White House climate czar Carol Browner told reporters yesterday that Lieberman is a crucial member of the "interesting bipartisan coalition" crafting the final bill.
Another source tells TPMDC that Lieberman has frequently met with Salazar, now secretary of the Interior, Browner, climate envoy Todd Stern, Energy Secretary Steven Chu and United Nations Secretary General Ban Ki Moon.
On health care, Sen. Amy Klobuchar (D-MN) said on Fox News this morning the Democrats are working with Lieberman, who joined his colleagues during their caucus last night. Like Vice President Joe Biden, Klobuchar said she is confident Lieberman will come around.
Senators have been echoing that all day, perhaps another form of pressuring Lieberman to see their point of view.