Well, we'll have another double something next week, followed by a halloween one. It'd be nice if Anet moved away from the reduced grind ideas (because they aren't fixing the real problems of the game) and do some things that are more fun oriented.
1. How about a random shout weekend where in PvE, every time someone uses a skill, a random shout will happen. It could be anything currently in the game or some new effects just for the weekend.
2. A while ago, I suggested a siege devourer vs NF wurm PvP arena weekend... That'd be fun.
3. New boss weekend... Add a few bosses that last just for a week-end and maybe give them greens that can only be farmed in that time.
4. Ecto-drop weekend, where every mob has a 3% chance of dropping several ectos when you kill it.
5. Pre-portal weekend. Add an alternate reality area of pre-searing ascalon where the searing never occured. It'd be level 20 or so and after the weekend, it'd be possible to return there whenever you want... and at a portal from all the chapters.
6. Elite weekend; where in both PvP and PvE everyone is given a bar of 8 preset elites based on primary and sub class (maybe 5 from primary 2 from sub and a res).
7. Guarenteed gold weekend, where all treasure chests opened with a lock pick will give you a gold item or an elite tome, gaurenteed.
8. Green vendor weekend... a merchant appears in each town selling all non-endgame and non-elite area greens. All greens are sold for 5k.
9. Emperor's clothing weekend: all armor is invisible.
10. Death by bunny weekend: all mobs including end-game bosses look like bunnies for a weekend.
11. Gwen's revenge weekend... in all HM zones child gwen will come back as a boss-like mob with multiple elites on her bar and travel in packs of 10 (one of each class). For example the el version might have mind blast, SF, SH, mist form, invoke lightning, and sandstorm. Killing all ten of the gwens will be required for vanqing the zone, but they'd drop a Green Flute specced for that gwen's respective class as a random drop.