I agree with endrance that the Daily boss bounty/missions etc from GW1 would be a nice way to provide a degree of randomness to current GW2 dailies. However, there may be substantial limitations for some players that cannot access certain mission areas.
Anet had a great idea when they went about creating a dynamic environment, but a lot of the events really are getting repetitive. Something like the K / L faction wars was a good way to keep things fresh in GW1, but I suppose we have WvW for that.