Here's my toughts on this subject lately: Raids succeed largely because of the efforts of a small handful of people who work hard to get the right group of people to come and perform well. A 5-man doesn't require the same level of commitment or anything, obviously, and getting group composition should be less taxing as well. However,I am convinced that to have ANY organized guild events with any sort of regularity/reliability will absolutely require that a handful of people step up and really take charge to make it happen.

What does that mean? It means making events on the site, it means being social with the more casual members of the guild to try to get to know them on a level where your invite to a group is from a "friend" rather than "some random guy I see in green chat." It means that when those few leaders get a 5-man going, they try to have a plan ready and are capable of leading the other 4 folks through as quickly and effectively as possible. It means that someone has to take the time to keep people from getting their feelings so hurt after a mistake that they never group with those people again. It means someone has to be willing to whisper like crazy to fill that last spot, even if it means *gasp* whispering someone you've never talked to! (We even have to do this for raid NEARLY EVERY NIGHT.) It means someone has to find the dedication and patience to make it happen. That someone cannot/will not/should not be any of the current guild/raid officers. It needs to be one of those "casuals" that wants it to happen bad enough to overcome the initial challenge and discouragement. (Ask Atar sometime how long he had to be patient before LF1M really took off.)

Ideally I think we should set up an "off-raid" alt day or two where the non-raiding mains and raider-alts ge  do stuff (ummmm, mAlt maybe???)  however, focus not on the 10-25 mans, but the 5-mans.  the mAlt runs we have now are outstanding and should not go away, it's a great way for non-main raid guildies to get the flavor of 25s and 10s, as well as get the up-and-comers used to raiding with DF in general.

In addition to this, set up a VERY consistent schedule of non-raiding main group nights, where the 5-mans can be run consistently to progress through chains or w/e (reg or heroic, or perhaps both).  I think that if there were 2 5-mans scheduled per night (one reg, one heroic), there would be some stirring of activity amongst those that may feel a little left out of the spotlight, or don't want to be in the spotlight :P.

I would try to specifically avoid raid nights (Hamfist and LF1m specifically), so our raiders get a chance to log on with their alt tunes and goof around as well if they feel like it.

 The other thing to consider is trying to get the non-raiders goingh during raid times.  The most difficult issue regarding that suggestion it to get more non-raiders to frequent the guild site.

I love the idea, but I feel it will be a long arduous journey with a level of frustration to get people to cooperate.  I think if a few of the non-raider people that are active on the site really try to push the site, we may get some results.

 We would have to be rather expressive to the non-raid folk while in -game regarding the guild site. Reallyencourage use of thesite without being harsh or overly demanding.

on a side note:
I have spoken to Garreth about this very issue, and I feel there are alot of non-raiders who want to stay that way (non-raiders), and feel that making the extra "push" to getting active on the web-site may make them feel that they have gone beyond WoW being "just" a game.