Ideally the defense appropriations bill will be passed by Friday the 18th. If not then a further continuing resolution (CR) must be passed. Both the House and Senate plan to move out on the bill which would be good thing as this would allow DoD to execute their proper budget rather then operating under the CRA rules which limit new contracts. Unfortunately as this is now the last bill of the year the Democratic leadership in Congress plan to add a great deal of things not related to defense with the idea of getting them passed.
The biggest add will be an increase in the Federal debt ceiling. This limits how much money the Government may borrow to fund itself. If spending continues at the same rate as it currently is the ceiling will be breached before 2010 even starts. The plan is to increase it by almost two trillion dollars. Republicans and some others criticize this as just allowing more and more debt rather then trying to control spending. The problem is that the way the budget is structured more debt is needed at least in the near term until revenue grows assuming the economy starts doing the same.
The second jobs bill will also probably be added to defense. This is a plan to try and make a dent in unemployment through loans and credits to businesses. This is pretty a much an admission that the initial "stimulus" bill in March failed to do so and more is needed. The estimate for this is about $70 billion.
The assumption is that because defense is so important that there will be little motivation for legislators to vote against the bill no matter what is attached. The Defense Department and its contractors need the appropriations bill passed. It becomes and easy vehicle for all of the other things Congress wants to get done. Is it the best way to do this? No but Congress has put itself in theis place.