This information comes from the box/manual for Call of Duty: Black Ops on Wii…

“Expand your experience with downloadable content from the Call Of Duty Store. All downloaded content includes new features and maps found in Call Of Duty: Black Ops.
**Additional fees may be required for Add-on Content. This game allows you to connect to the internet and download add-on content (such as data or services) for Wii Points. Please keep the following in mind when downloading licences for add-on content…” etc. etc.

We have never really seen footage from the Wii version of COD..why? your guess is as good as mine.

Link