Hmm, I'll just throw this here. I don't really think Nintendo or even we ourselves really understand the Wii phenomenon. It's probably a discussion we should get deeper into sometime.
Here's a list of Wii million sellers from Wikipedia. These are world wide sales.
According to
destructoid, Nintendo said at an investors meeting that Wii had 79 million sellers. Not sure what all those games are. I believe this was mentioned before Donkey Kong Country Returns and Super Mario All Stars, etc, showed up.
I know within Wii's launch and first year there were success stories with titles like Super Swing Golf (Pangya), Trauma Center Second Opinion (Atlus' best selling game ever before Catherine/Demon Souls, I think), and Resident Evil 4: Wii edition (didn't this sell better than the GameCube game?).
Not sure about Elebits, but Dewy was made by the same team so I guess that was a success too.
Some titles flopped, but I doubt titles like Soul Calibur Legends would've been doing gangbusters on any other platform. Wii got a lot of spin-offs and shovelware and sequels to those spin-offs and shovelware.
Problem with Wii was that the big new games stopped coming. After New Super Mario Bros. Wii/Just Dance 3 and Wii's biggest december holiday, and after retailers cracked down on the shovelware, there was Monster Hunter and then.... I don't know. Next big release wasn't till the end of that year with DKCR. Super Mario Galaxy 2 did okay, was a decline from the first Galaxy, and didn't do much for hardware and well that Metroid game that year was a joke so we'll forget about that one. Yeah, it was downhill from there. Mostly niche titles until Christmas.
I believe Nintendo hoped Wii Party would sell, but that didn't happen. People were tired of the same stuff already. The year after that was just really bad with software support. PS3/360 were where the cool new games and gadgets (kinect) were at at that point and the prices were coming down.