I'll post my review when I'm finally finished with the game, but I'll elaborate on a few of the questions you all have asked here, as there is so little information on this game out right now, it's practically criminal.
Re: Job System
The job system in Opoona is not like Harvest Moon, or a dating sim, or anything else where it plays too much into the storyline. Basically, the game progresses through the jobs that you find from town to town, which offer you little sidequests and minigames that allow for some extra diversions between the larger Ranger missions, which Opoona is really all about. In each town there are anywhere between 2-4 new jobs that range from farming and mining, to being a hotel clerk and selling clothes at a designer boutique. A few of these are necessary to advance the storyline immediately, while others may be later on (I haven't completed the game, so I can't say if fishing suddenly saves the world 30 hours in). On a whole they are fun little activities, and can be anywhere from picking up trash with hoverboard attachments, to beating the crap out of fish underwater. There are a few jobs that carry over from town to town, while others are just a one- or two-shot affair that net you a little cash and some fame/friendship/"personal growth."
The meat of the game comes from the ranger system, in which Opoona goes out into the wilderness and fights off rogues and saves people and such. Those progress your overall rank, and get you deeper into the story that you're trying to unravel as things go on.
Re:Battle System
I said the Opoona's battle system had "surprising depth" because of the way that it is much more than simply flicking the controlstick mindlessly until everyone is finished. While this may be the case early on, you can fire you BonBon in four different directions, and the strategy comes in how long you hold down the control stick (resulting in a stronger bonbon shot), or which direction the stick is held in (up, down, left or right). You can make the bonbon fire over smaller enemires by holding back and selecting the enemy behind the smaller one, or swerve around it by holding the control stick left. All the while you're doing this in real-time, so pansies like myself who usually choose "wait" in Final Fantasy should prepare to finally man up and experience some chaos. Don't go into it expecting a tactical RPG, but there's definitely more to it than just pressing the controlstick back and watching the bodies fall. Certain enemies take more damage from certain tosses of the bonbon, while other times you'll be forced to loop around bombs in order to strike foes. It's more than I expected, I'll admit.
A lot of time went into the game, and it definitely shows. There are a good amount of optional sidequests including hidden codes you can redeem for goodies, art pieces to find and enjoy, and lots of jobs that give you rewards for continuing them when you need not to. It's very easy on the eyes as well - even though HiDef GAF will probably disagree, Opoona actually looks pretty good for a Wii game. I personally enjoy the graphics and overall aesthetic of the game, but I know that it's not going to be everyone's cup of tea.
Be advised that it definitely has a lot of generic JRPG elements, so I'm sure I'll start saving the world in a matter of hours, but it's still enjoyable no matter how trite. The localization is noticeably poor, however it doesn't really "kill" the game, so much as you'll just have some chuckles every few screens. It will occasionally result in you answering "yes" to something you meant to say "no" to, but usually just results in some awkward phrasing and occasional mistranslations ("envelope" instead of "envelop," etc.). Also there is a bit of trekking back and forth, but the hoverboard makes things a bit quicker, and it's usually not to fruitless as you can generally do other things from place to place.
I'm enjoying it so far, but I can see how it couldn't be for everyone. Yeah, the fact that Opoona is practically a fisher-price playtoy on an adventure with a ball will detract some, but if you're looking for a solid (and quirky as all hell) JRPG experience for the Wii, I don't think Opoona would be a bad choice. It looks to be somewhere around 30-40 hours right now, and I'll confirm that once I see some end credits roll by.