PC133 will more than likely stay at the same price or drop slightly for the next 3 months... Nothing is ever guaranteed though!
It really all depends on Rambus and DDR and how quick demand switches to one of the two (or both). If demand takes of for rambus (a sucessful 850i launch? yeah right hehe) then there will be less demand for PC133 and prices will probably drop. Same thing goes for DDR, (if the 760 takes off, VERY likely hehe)
It takes manufacturers awhile to change there process to accomadate the demands of the memory market. If DDR is a disappointment and Rambus stays the way it has been then prices for PC133 may spike.
Everything in the memory market comes down to the age old battle of supply and demand.
You see the memory manufactures have to plan ahead for what they THINK the market will want and if they guess wrong then they produce too little old ram (PC133 in this case)and overproduce the new ram (DDR, Rambus) That is why a stick of EDO will cost you WAY more (per MB) than getting a stick of PC133. Not very many people manufacture EDO anymore, if any, but there are still a lot of old 486's and Pentium MBoards that can use more memory. (i.e. still demand but no supply)
I think most of the memory manufacturers are at an impass right now and are trying to determine whether DDR or Rambus is going to be the memory of the future. So instead of gambling on a new tech, they are cranking out the PC133 because they KNOW it will sell... for now. (i.e more supply and less demand than supply (but still a lot of demand)).
Also, like PM said, the PC makers have started to cancel some of their buys because they think they have more than enough RAM for the Christmas buying season. If you look at the trends it almost always happens this way in the Q4