Can a hefe be kegged, or is bottling preferred?
If kegged, how is the yeast kept in suspension?
I keg my wheat beers and they always drop clear and bright eventually. Wyeast makes an additive, TANAL A, to prevent that:
http://www.wyeastlab.com/com_b_productdetail.cfm?ProductID=12
I have the same experience, but depending on the yeast used, this can take quite a few weeks. You can always shke the keg to keep the yeast in suspension as well.
Add a tablespoon of whole wheat flour the last 5-10 minutes of the boil, it will add enough starch haze to keep your beer hazy.
Wondering how any of this (keg settling, additives) impacts taste/aroma profile, or is this for appearance only? (Not dismissing appearance concerns, just wondering)
One of my favorite summer beers is NBB Sunshine Wheat. Obviously not a heffe but I like a good, cleared wheat. Most of the wheats I’ve brewed have been belgian influenced or american wheats. I like to crash them to help them clear up a bit. Just my preference I guess. Not a huge fan of drinking raw yeast! Anyone know how the commercial guys keep their heffes cloudy in the kegs? I’ve never had a glass of clear Widmere!
I should have been clear and specified German Hefe.
If the yeast takes weeks to drop out, I’m guessing the flavor profile will gradually become less and less banana/clove-like.
This is what I’d like to avoid, although I don’t think the keg would last more than 3 weeks anyway. Perhaps tipping/shaking the keg at the 1 1/2 week point would be sufficient to maintain the flavor profile.
Interestingly, when an Army-acquaintance of mine was stationed in Germany, he drank mostly hefes. He said it was always served from a bottle. Hmm…
On another note, do you keg-carb the hefes for a longer period, or at at higher rate/vol?
Ya gotta keep shaking it anyway to kinda figure how much you have left. 
I’m so bad at it, the last gallon or so is really hard to judge.
I usually keg my wheat beers (both German and American) without issue. If you want the Hefe to remain cloudy, just give it a light shake periodically. Personally, I wouldn’t add any flour to the beer. German Hefe is served cloudy because the yeast in suspension gives it unique flavor characteristics. You’re not going to get those flavors by just adding flour. You’ll just get the Hefe aesthetic.