Betta's have no heat on the shelves at stores, and I somehow doubt that is what causes their demise at Wal-mart, plus I doubt it will be very cold..I'm sure they don't want uncomfortable guests at the reception. Most of the vases that they put those fish in a quite large, so I don't think they will be cramped, most are 1/2 gallon...no smaller then a beanie box. I'm sure they will have fresh, clean water...so as to not gross out their guests with smelly, dirty, uncleanliness. As mentioned before, most come with the plant in a plastic cup sitting in the vase, so there is always a gap (no cup is gonna fit perfectly with the rim of the vase) for air. And unless this is one wild shindig, most weddings I've been too that had pretty stuff all over the tables, wasn't a loud, wild affair. And I have fairly loud music on in my office at work sometimes and in teh car on my way home (they come home on the weekends for now)..they really don't seem to give it a second thought.
I think it'd be cute to give them away to the kids afterwards, I personally think they'd far way better then sitting on a shelf unattended at wal-mart somewhere. And it's much better then those bags of rice..which DO cause problems...with the local wildlife (birds) and such.
:shrug: