This June, none other than Hudson's Master Higgins himself, Takahashi Meijin, revealed early plans to make a new Adventure Island game for the Wii. We've heard almost nothing since then, until today!
Hudson has told WiiWare World that a new Adventure Island is on the way to Europe for this April. We can assume it'll show up worldwide at some point as well, like every other Hudson WiiWare game.
In addition, the company has announced a new WiiWare FPS called Onslaught, whose defining characteristic is that it isn't Adventure Island. We're willing to look past that flaw, however, for a four-player online multiplayer WiiWare FPS (seriously) about "blasting a massive number of enemy creatures to feel the exhilaration". Onslaught is set for European release in March.