I consider this a bit of an exploit but I do not believe SOE will do anything about it.
There are two ways to gain guild levels faster then intended.
Purchase or farm status items. Have your entire guild do this but do not sell the items to the status vendor untill you have a sufficent amount. Make sure all members have been in the guild for at least one week so you do not loose any status by removing them. Then remove all members except for 6. The remaining 6 should sell all of the status items to the vendors that give status for them (either the quest givers in Qyenos/Freport or the court merchant). Once all status items have been sold, invite all members back to the guild.
No member will loose personal status and the guild will keep all status attained as long as the members have been in the guild for a week or more.
Raid lower level raid zones with a full 24 member raid. Do this after all status items have been sold with the lower membership to maximize results. If you are a guild that is capable of raiding T6 zones, raid T5 zones instead and hit as many as you can as fast as you can. If you are skilled you should be able to hit Spirits of the Lost, Deserted Mines, Cove of Decay: Epic Angler, Crypt of Vox, Drayek's Chamber, Echoes of Time, Firemyst Gully: Shattered Stillness, Meeting of the Minds, Obelisk of Lost Souls, Sundered Splitpaw: Anvilpaw's Grotto, The Commune of K'Dal, and The Drowned Caverns: Brutal Acts of War. Each named encounter should give 2k-12k each encounter per person. So in a 24 player raid that is 2k*24=48,000 personal status minimum per named encounter. The actual amount that goes to the guild will depend on the number of members in the guild, but as you can see, these are very large amounts of status for very easy encounters. If your members are over level 61, you may need to mentor to 61 in some encounters to turn the mobs green. You will not get status for grey encounters.
By using the two methods (and assuming that you have 50 stacks of T5+status items) you should be able to easily get from guild level 40 to guild level 50 in 3-4 days of raiding.