The next iteration of the Wii will bring HD visuals, as well as improved storage capacity and will see the light of day in 2011, according to recent speculative reports.
A report on What They Play, authored by ex-1UP staffer John Davison and picked up by Edge Online, cites multiple sources detailing the Wii's successor. It's expected to retain the Wii name that having been initially mocked is now a byword for the expanded market the console has carved out. The new console will also address key issues with the current Wii, namely the lack of true HD visuals and the lack of storage space, and will mark a generational leap similar to that of from the original Game Boy to the Game Boy Advance.
Nintendo's R & D budget has reportedly tripled since the launch of the Wii in 2006, providing compelling evidence that a new console is in an advanced stage of pre-production. Don't expect any announcement soon, however – with the Wii still enjoying phenomenal success, it would be unlikely that Nintendo would want to spoil the party any time soon.