too many. Super Dodgeball Brawlers, Bangai-O Spirits, Final Fantasy Tactics A2, Etrian Odyssey II, Space Invaders Extreme, Arkanoid DS, Rondo of Swords, Jake Hunter: Detective Chronicles, Harvest Moon: Island of Happiness, and The World Ends With You are just a few that we can name on the spot, and all of these will be out before July starts.
Unless you have abundant amounts of currency, though, you probably can't afford to buy that many games in such a short period of time. Also, money isn't the only problem. Supposing that you could afford everything you wanted, you wouldn't even have the time to play them all.
Narrowing down the field is tough, but necessary. What games that are coming out in the next three months do you consider must gets? And they don't have to be chosen from the games listed above, so go nuts.