Absolutely, especially the bigger companies. I think Ubisoft has done a decent job of it while Konami's Wii offerings are pretty underwhelming.

Throwing Epic into this argument (which I don't think you did, Benga) is ridiculous though. They specialize in high definition content and they have to be one of the most profitable third party companies out there right now. They've become the default engine for mid-sized developers over the past few years and now even some of the heavyweights like Square are using their UE3 engine. 

So many assumptions being made here ...

Third party publishers and developers do not live in a vacuum, and they're not completely devoid of independant though and intelligence. They will all act on their own in an attempt to maximize their personal results and profits. Some third party publishers and developers may "ditch" or avoid the Wii because it does not suit them or their larger strategy (Epic Games would be an example of this), while most will see the large userbase and lower development costs as a way to get the best return on investment in order to maximize their profits.

What does this mean in terms of games?
Some publishers and developers will see the Wii as an opportunity to tap into a new and growing market segment which they have been unable to tap before, while others will realize that the Wii is (currently) being bought primarily by conventional gamers and they will try to market towards these gamers. This means that the Wii's library will probably grow with lots of diversity ...

In contrast, I suspect that the PS3 and XBox 360 are likely going to see less diversity from third party publishers and developers in the future because the high development costs will force publishers and developers to avoid taking risks. Publishers are going to look at the fact that (pretty much) the only games that are ensured to break even and turn a healthy profit are First Person Shooters, Racing Games and Sports games that are released on both platforms. The days of the quirky game produced by the small developer will be over for the Playstation, and there will be mountains of games about space marines fighting off aliens in a destroyed urban environment.

There's a lot of false assumptions floating around in this thread.

Developing on the Wii vs developing for the HD consoles isn't necessary that cheaper.

If you want a title with big sales ( and the major developers need that, they can't go for small titles/small cost/ medium revenues and still manage to keep growing) developing on the Wii vs developing for the HD consoles is just a choice of wether you spend your cash on R&D or Marketing ( because it takes more $ to attract the attention of Wii owners than HD console owners, that's what you get with a more casual market and Ubisoft confirmed recently that it is indeed what they are experiencing ( Wii/DS games require more marketing than traditional games to be successfull).

How are you sure about that? if that happens, and if its exclusive then no doubt Wii will win this war.

Sorry PC won. Didn't you get the memo?

Ban bets aren't allowed (do you get banned for taking a ban bet?) and I wouldn't take one anyway. One week Avatar+Sig control.

I'll even help you by putting a time limit:

Within a year a Castlevania AND Kid Icarus game will be announced for Wii. If not you win.

I think you're misunderstanding what was being said by Ubisoft ...

He wasn't saying that "It costs $2 Million to make a Wii game and $18 Million to market it, and it cost $20 Million to produce a HD game and we don't need to market it, so the costs are roughtly the same" ... What he was saying is "If you wish to market a game towards non-conventional gamers you need to spend marketing money to make them aware of the game"

He was commenting on it not being simple or easy to produce a "Blue-Ocean" game that sells like crazy, and that publishers who are simply dumping games on the Wii with no marketing shouldn't be surprised that their games aren't selling.

Wii has already won and without the need for any big 3rd party titles.  The hardcore will not and cannot decide the 'console wars'  they just aren't as numerous as the larger marketplace.