The top-tier first-party games (Super Smash Bros, Wind Waker HD) are expected to be announced/demoed in a few weeks at E3, but by the time they hit the shelves, it may be too late.
Nintendo has a pattern of overdelivering with the consoles, and then underdelivering with the games available for said console (at least at first).
EDIT: I should add that this is a relatively recent pattern; the N64 and the Game Boy Color are definitely stronger as platforms (with all their available games) than as consoles. Somewhere between the Game Boy Advance -> 3DS (which has terrible game availability for an awesome console) and the GameCube -> Wii, the pattern reversed itself.
The European launch (5? 6 months later) had those two, plus Star Wars: Shadows of the Empire.
Also, the ping pong game (and 100 pin bowling) in Wii Sports Resort is probably worth the money for the whole disc, which is another way to get the dongle.