I got the game earlier this week (along with Fragile) for my birthday, and after several days of on-and-off casual play (an hour here, an hour there) I can say that I definitely enjoy parts of it, but like its predecessor it's purely a tech demo for hopefully better games in the future (namely Zelda). Of the 12 events, probably the 3 I've gotten the most enjoyment out of have been Swordfighting, Basketball, and Archery.
Swordfighting just feels right, even with the incredible annoyance of having to recalibrate the Motion + every 3-5 minutes. Duel mode has the potential to be fun, but I pretty much spent the first 1,000 points just pulling out apparently these Miis' fatal weakness: the "swimming *****-slap" (seriously, I've had entire rounds go by where I do nothing but slap the Miis off the platform, without them ever being able to attack). Speed Slice is a lot of fun, but the real winner seems to be Showdown as that's where the actual mechanics of the swordfighting shine (attacking from the right angle, blocking, etc.). It's a real testimate to this mode that my best friend, who loathes motion control, went through a round of this and basically said "yeah, I could enjoy a Zelda game like this." My only complaint about the mechanics is that the old legacy issue of the Wiimote not recognizing thrusts very well still seems to be in effect.
Basketball is a bit of a guilty pleasure for me, because I enjoy it probably more because I'm a basketball fan than because the mode is actually any good. There's just almost no depth to the 3-on-3, and the 3-point shooting contest (though enjoyable) can only do so much. Archery is very nice, though I have to smirk at the game's assertions that the Wiimote is supposed to be the bow, considering 9/10 getting a proper aim usually results in me eventually pointing the Wiimote at the screen.
As for the other games, there are some decent ones in there. Frisbee Dog is surprisingly fun, as is its Golf mode (it's more fun than the actual Golf game, that's for sure); Air Sports is kind of relaxing (though I wish there was an actual throttle instead of continually thrusting the Wiimote forward for Speed boosts), though I found it harder to control the plane holding it paper airplane-style rather than just holding the Wiimote like normal; Bowling is as awesome as ever; and Table tennis is fun in short bursts.