As mentioned in the announcement of Squibs Arcade, Nintendo of Europe is holding a WiiWare (and DSiWare) media summit this week. During the event, Nintendo released a list of WiiWare and DSiWare games planned for release between April and June.
On WiiWare, the biggest news is Cave Story! Even though we knew it was scheduled for release in April or May, seeing more confirmation of that (for more regions) is great! Swords & Soldiers is also on the way. In addition, there are also a few games we haven't heard much (or anything) about. Each game has a brief description in Nintendo's announcement.
Crystal Defenders R1
Icarian: Kindred Spirits
Overturn: Mecha Wars
Robocalypse: Beaver Defense
Swords & Soldiers
In DSiWare, the most exciting title (to us) is Nintendo's Art Style: PiCOPiCT, a retro-Nintendo-themed puzzler with reinterpreted NES music by YMCK.
A Little Bit of... Dr. Kawashima's Brain Training: Maths Edition