“Everything that is happening between now & 2010, except for any Supreme Court appointments, can be changed...it’s just up to the GOP and every conservative in the country to do all he & she can to make sure that this whole mess comes to a screeching halt.”
The idea of trying to bring the mess to a screeching halt between now and January 2011 is now lost with no threat of a filibuster, assuming Specter votes for cloture with the Dems, which he will otherwise he would have gone independent. This is a train that will not stop for a while, it has now left the station and we are ph&cked.
As far as reversal after Jan 2011, in theory yes, it’s possible. But if you look at two practical obstacles, it seems very unlikely.
The first is that assuming a Republican revolution and takeover in 2010 (which is a HUGE assumption), Obama will be there for the veto until at least January 2013. This gives an additional 2 years of life for the new bills.
The second is the history of social outlays in the United States. Once implemented, they quickly take root and are then expected by both Democrat and Republican alike. Anyone that has attempted to dismantle Social Security, unemployment insurance, SS disability, SS death benefits, Medicare, Medicaid, etc has been met with swift and firm political blowback on both sides of the aisle.
The reversals may be possible on some legislation such as cap & trade or other liberal tax related laws or schemes assuming a Republican president and Republican house/senate supermajority in Jan 2013 (remember, Dems could use filibuster then too).
But with regard to universal healthcare and other social program expansions, if given a full four years to sink in, it will be politically impractical to reverse them.