I really think we should wait until christmas is over before we give any statements of any kind regarding Wii sales.
The decline in sales clearly are a result of an ongoing software draught. Mario Galaxy 2 was the only million selling game released this year before we got Wii Party. That is a severe software draught and hurt sales a lot.
If the games released during the Christmas period are enough to push the Wii up again then there's a good chance it will lead the market in 2011 as well. If those titles fail to push hardware sales back up then there's a good chance the Wii won't lead the market in 2011.
How severe this software draught was can be seen by looking at this weeks numbers. Wii sales jumped significantly on the back of Just Dance 2 and Wii Party and according to Iwata these kinds of games usually take some weeks to really push hardware sales. There literally have been no games in 2010 to push momentum.
Posting predictions on the basis of "assuming" that holiday titles will / won't push hardware sales is just guessing.