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 - £26.99 (amazon)
05 - Yoshi Touch & Go - £29.99 (GAME)
20 - Pac Pix - £29.99 (GAME)
27 - Need for Speed Underground 2 - £24.99 (Amazon)
?? - Ultimate Brain Games - £29.99 (GAME)
June
03 - Ridge Racer DS - £29.99
24 - Another Code - £29.99 (GAME)
30 - Madagascar - £25.99 (Amazon)
?? - Ultimate Card Games - £29.99 (GAME)
July
01 - Bomberman - £26.99 (Amazon)
01 - GoldenEye: Rogue Agent - £24.99 (Amazon)
01 - Tom Clancy's Splinter Cell - £24.99 (Amazon)
?? - Mario Kart DS - £29.99 (GAME)
?? - Metroid Prime: Hunters - £29.99 (GAME)
September
?? - Castlevania - £29.99 (GAME)
?? - Prince of Persia - £29.99 (GAME)
?? - Sharman King - £29.99 (GAME)
?? - King Kong - £29.99 (GAME)
October
?? - Harry Potter & the Goblet of Fire - £29.99 (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.