I know they can have the option to have people visit the other server, but would it be possible to have a guild vs. guild where the top guilds from Diamond & Sapphire compete? Maybe it would be a good one time a year event.
I shook my head going "waaaahh?" at the bolded part, then i thought a minute, you can have characters on both servers and easily change servers, not sure if thats what you mean.
But +1 on this, i believe that they should add a option where both servers can interact, such as in GvG (outside of the elimination, where guilds from each server, or 2 guilds from 1 server itself, can come together and battle).
And, this should also be placed in the suggestions area.