As a leader and as a player you need to understand this is how things are. But I do feel there are ton of good things, especially for my group that I'm getting out of this.
First of all Diablo. To be honest, best thing to happen right now. Despite the decrease in interest in WoW, our performance and attention during raid did go up in my opinion. I always encourage people to play other games and play other aspects even if it's just pvp when you're a pve'r. It does make you better. We even stopped doing our ten man alt raid for Diablo and I think it was a better idea then "practice" or gearing in WoW.
The one and greatest problem I see is people and the negative/destruction attitudes. This is something that is just more apparent now because there is less structure in my option. With things on farm, there is no clear roles needed. I've had a ton of resistance from people for small things that have been totally blown out of proportion.
I STRONGLY ENCOURAGE EVERYONE. You are still in a social environment, there are things that are acceptable, things that make you a better person and things that make life easier for everyone around you. Which leads to my next point.
Not one person is "needed" or "required" at this point. Don't let this stuff fly. This is a very good opportunity to get those good players and good members that will be sustainable. Try to identify those that are impartial and have good morales and the skills to manage conflict and get them in leadership roles.
The best players should not necessarily be your officers and raid leaders.