I'm predicting 2009 to be the Wii's peak year in terms of hardware sales, but I don't think you'll see too much of a dropoff in Wii sales until 2012.
"The worst part about these reviews is they are [subjective]--and their scores often depend on how drunk you got the media at a Street Fighter event." — Mona Hamilton, Capcom Senior VP of Marketing
*Image indefinitely borrowed from BrainBoxLtd without his consent.