I double checked Nintendo for official dates but theres only a couple and it's their own software. So here's some retailer dates from the UK. Guide prices included, shop offering price in brackets. Confirmed dates in bold, let me know if you can confirm or change any:
Indicative dates for Europe:
May
05 - Star Wars Revenge of the Sith - ÂŁ26.99 (amazon)
05 - Yoshi Touch & Go - ÂŁ29.99 (GAME)
20 - Pac Pix - ÂŁ29.99 (GAME)
27 - Need for Speed Underground 2 - ÂŁ24.99 (Amazon)
?? - Ultimate Brain Games - ÂŁ29.99 (GAME)
June
03 - Ridge Racer DS - ÂŁ29.99
24 - Another Code - ÂŁ29.99 (GAME)
30 - Madagascar - ÂŁ25.99 (Amazon)
?? - Ultimate Card Games - ÂŁ29.99 (GAME)
July
01 - Bomberman - ÂŁ26.99 (Amazon)
01 - GoldenEye: Rogue Agent - ÂŁ24.99 (Amazon)
01 - Tom Clancy's Splinter Cell - ÂŁ24.99 (Amazon)
?? - Mario Kart DS - ÂŁ29.99 (GAME)
?? - Metroid Prime: Hunters - ÂŁ29.99 (GAME)
September
?? - Castlevania - ÂŁ29.99 (GAME)
?? - Prince of Persia - ÂŁ29.99 (GAME)
?? - Sharman King - ÂŁ29.99 (GAME)
?? - King Kong - ÂŁ29.99 (GAME)
October
?? - Harry Potter & the Goblet of Fire - ÂŁ29.99 (GAME)
Cube Europe have release dates
here. Some of the game data hasn't been updated since January so some of those dates are already wrong and / or are guesstimates. Until Nintendo divulge more release dates in Europe this is the best we're prolly gonna get.