No, totally different.
Dual Channel refers to how the MB accesses the memory.
DDR2 is a new package and new standard for "higher speed" memory.
DDR can only be used on DDR MBs with single or dual channel controllers.
DDR2 can only be used on DDR2 MBs with single or dual channel controllers.
To take advantage of dual channel you need two sticks on the MB, preferably of the same size and speed ratings or things get complicated.
The names are confusing.