Will they be able to participate with 24 players on screen + however many enemies?
Honestly as a proud PS3 player, I'm probably not going to do this until I either upgrade to the PS4 or the PC version. The problems during fates and the lag during 8 man raids is enough of a concern to realize the PS3 version won't be able to cope. However, there is one possibility that I'm wrong. Yoshi seems to think that these parties would not be in the same vicinity so that would be great for PS3 users. If this turns out to be false, the PS3 will lag behind and probably just get people killed.
I'm a huge fan of the PS3 version, but there are some limits to what it can do. No PC could run the game on 512mb even on XP. LOL