"Casuals" hardly ever finished games when platformers like Mario were popular. That never stopped them from buying more games (they're entire new worlds to explore). I don't think I beat half the games I had on my NES when I was a kid.

Also, Donkey Kong looks pretty damn amazing (the animation is very fluid), the graphics are as good as it gets for 2D games. I can see it being marketed well, and its 2 player co-op is good enough for kids.

My guess:

Kirby: 2-3mil (slightly under Kirby Super Star DS sales, art is too niche)
DKCR: 9-11mil (huge in the US)

I see your point but Wii's audience is totally different than NES/SNES with about half being female and a lot of previous non-gamers.  So far the Wii audience has shown they'll go for a new nifty idea - once.   Look at Boom Blox, Shaun White, Endless Ocean, No More Heroes, etc., etc.,  All sold well but with sequels that don't come close to the original's numbers, often despite being markedly better.   Even this year's Tiger Woods looks like it'll be a sales failure, because people don't see why they should upgrade from TW'10  (Should've put putt-putt on the cover EA).    Although there's been a ton of party games, none have sold close to the original - Carnival Games.

Multi-player 2d platform has been done now, and done with 4 players, it'll be a hard sell to get this crowd to buy the same idea again with only 2 players.

However, as I mentioned, these are well known franchises with an existing audience.

There's a huge difference between sequels and an entirely different franchise, though. Sure, Donkey Kong plays a lot like Mario, but it definitely isn't the same. I don't think 2D Mario bars success for all future 2D platformers.

Heck, take Wii Sports Resort as an example, it did amazing well, despite essentially being a sequel of Wii Sports (though admittedly it does come with WMplus). You predict Wii Party to be huge (20 million), despite it not being so different from many other games that have already released.

I still see NSMB Wii ending well over 20 million sales, so I don't think expecting DKCR doing just under half that is too crazy, but we'll see.

Donkey Kong Country Returns__8.4 Million

Kirby's Epic Yarn__3.1 Million(Though it should get over 10 Million)

DK - 4-5 Million

Kirby - 1-2.5 Million

I get what you're saying, and I agree, but I would like to point out that no one beat more than half their NES games.  The games did everything they could to make sure that you never saw the end credits: lots of them didn't even have an ending beyond "Good job! Play again?"

I can see DKCR reaching 10m. I think it is going to be Nintendo's next big "bridge" title and it will be marketed as such. Plus, the DK franchise is HUGE! Everyone knows it.

Kirby is harder for me to estimate. I have read before that Kirby is really popular in Japan (like 1m popular.). Not sure how popular it is in Americas and EU etc. So, as a total guess i'm gonna say 1.2m Jap, 1m Americas and 500k in others. 

So that makes 2.7m approx.

Donkey Kong will sell 10 million before the Wii dies, but it's going to be a very leggy game. It has a huge fanbase from the SNES days, and a new fanbase from the noobs who played New Super Mario Bros Wii and want another 2D platformer by Nintendo this holiday season. I think Kirby will reach 3 million over a similarly long time, making it the best selling Kirby console game of all time.

kirby epic yawn 1 mil

donkey kong jackass county 3 mil

Kirby will do around 2m, at max.

DKCR on the other hand... the sky is the limit. It's effing DKC for God's sake, ON the Wii and after a huge wait.