if soundscan's sales is always lower than oricon sales (like 50 - 60K), then we can assume that the first week sales of (m)u was around 430K copies. Minus the number from oricon (654K), then we can see that the second week sales is around 210 - 220K. so (m)u's first to second week drop rate (50%) is better than MY STORY drop rate, which is around 67%.
I'm not sure if it can break 1 million copies this time. It really depends on the word of mouth (is that what it called? i forgot
). People like it, then it can struggle for 1 million copies. People dun like it.. mah... 900K is the max.