According to new information we've scooped up from MyWii.com.au the game will not feature the Balance Board but will be played as a 2D platformer with the WiiMote held like a NES pad.
MyWii.com.au don't cite their sources (bah humbug!) but this is what they are reporting about the game:
Wario's newest adventure is [indeed] a side-scrolling platformer that will be making use of 2D artwork to showoff and depict the stages and characters. The game is being designed to make happy both casual and hardcore gamers so no one will be disappointed and with that being said there will be a total of 20 stages. Each stage will have a unique environment so you won't get easily bored of the stage designs with some stages being set in jungles, deserts and caves.
Controls however are a different matter with very few waggling of the WiiMote being incorporated and only being used to make Wario do a few extra special movies or controlling the vehicle that Wario will be driving. So how will Wario be being controlled, well like all Side-scrolling platformers the WiiMote will be held horizontally on it's side and most controlling of Wario will be done through the D-Pad and the 1 and 2 buttons.
The game is set to be released in Japan on July 24th. I must admit I'm a little excited about this game but I know the comparisons between this and Paper Mario are bound to be drawn. I'm glad 2D gaming is back "in" though.