Super Mario collection and Kirby continues to impress.

You don't impress just because you got on the list.  MARIO is impressing, Kirby, not yet.  I'm sure he will, but so far not really. 

It is impressive if  Wii games rarely debuts in the charts. Some people thought Kirby will never appear at all!

Oh, I don't disagree with that. But, I also think even a "sleeping" base works for something like DQ though, it's basically like Mario in terms of brand strength... even if people don't often play their Wii, they'll dust it off for Mario.  And in Japan, they'll also dust it off for DQ, with more mainstream games, the bigger absolute base invariably matters.

An "active" base tends to be a bigger issue for more focused or niche titles, and less so for mainstream ones.  Back when GameArts was developing Grandia for the Saturn, Famitsu asked them why they were making the game for Saturn and not PlayStation, and GA's response was basically that while PS had the far bigger base, Saturn had the more dedicated audience and they felt their specific game would actually do better there as a result (and it did btw).  I think it's much the same with PS3/Wii right now, the more "mainstream" stuff would do better on Wii (ie: DQ, Taiko, etc), the more "targeted" stuff would do better on PS3 (ie: Tales, Musou, etc).  Obviously there's specific cases where the opposite works out for whatever reason, but I think that's the general trend.