I just had my first ever genuine wedding party in the Sims 3: with generations, it's finally worth while. Actually, more than that...
It really felt like a party. I'm not sure if the images show, but there were at least fifteen sims walking around at some point.
I've ran into several other forums where people were asking how to hold a wedding and wedding party on a community lot. The main problem being you can't add wedding cakes (or any other cakes) to community lots. But this problem is easily solved: buy the cake shortly before your sims leave for the party, and drag it into their inventory. Once they're at the location, take the cake out of the inventory and place it wherever you want it. Problem solved :).
Also, as I said... the wedding party really, really, was worth while. I got four wedding gifts afterwards, worth over 60.000 simoleans. Honestly... with that much, I'm seriously considering killing off hubby number one and getting a second just for the dough.
Though I'm not sure if that wedding-gift part is new with generations. If it isn't... I really missed out on some easy money making in the past.