Memory Rebates: A push for ddr3?

I was just searching for some extra memory and I noticed that almost every good memory brand had rebates on their sticks and not just small ones, $25 for 2gb kits and $40 on 4gb. 2x1gb 800 cas4 or under $30, 2x2gb 800 cas 5 for under $60, cas 4 under $80. Are companies trying to unload their stock for a push to ddr3 in the next few months? If for nothing else than just to raise prices? I cant imagine that after shipping costs, reseller markups, and manufacturing costs (utilities, plant upkeep, packaging, people), that these companies are making much off of each set.

Then I go to look at any OEM builder an see "add $130 to go from 2gb to 4gb" and I just wonder...you could buy 2 4gb sets for the price of that upgrade with some money to spare.