As has been discussed to death (don't worry, though, the discussion continues to be rezzed, and even at 60% DP it is still very potent in battle), dervishes suck. One of the reasons they suck is because warriors, sins, rits (and in many cases even rangers) can all use scythes better than the dervish.
So, in order to give players an actual reason to play the dervish other than the tiny handful of decent builds they have (most of which have questionable advantages over the competition), I formally propose linking the number of enemies a scythe can hit to one's rank in mysticism.
In addition to it's current effects, mysticism will do the following:
At rank 0, 1 opponent can be hit by a scythe
At rank 5, 2 opponents can be hit by a scythe
At rank 10, 3 opponents can be hit by a scythe
At rank 15, 4 opponents can be hit by a scythe
The fact that some dervishes will be able to hit 4 opponents with a scythe should not significantly affect the game's balance (after all, that means a major or superior rune), and I feel that giving dervishes a reason to be played is far more important in terms of class and game balance than whatever effects hitting 4 opponents at once might have. After all, no one had a problem with the jump from 1 to 3 that NF introduced (I think

This won't affect the damage output of scythe warriors and scythe sins, but it will limit them to only hitting one opponent with the scythe. I feel that this is acceptable because, to be frank, these builds are destroying all purpose in the dervish as a primary profession. They need to be nerfed in some way, and limiting the number of targets they can hit seems like a fair way to do it.
Yes, I know that enchantment juggling should be brought back, and dervishes still won't technically be doing more damage and all that. But those sorts of changes require more than just minor tweaks, and they run the risk of upsetting the game balance. They're difficult, and quite possibly would require more effort than Anet is willing to spend fixing the dervish. This change is a simple one that would do nothing except make dervishes a viable choice of primary profession. Furthermore, it does not in any way inhibit further, more elaborate changes (such as the return of enchantment juggling and all that good stuff). The idea here, is that even if it isn't the most beautiful solution, a suboptimal solution is better than no solution at all.
So, c'mon, let's throw the dervish a freaking bone already. Please? He's been waiting very patiently, you know, and I think he deserves it.

EDIT: Ok, some people are missing the point. This thread is NOT for discussing the best ways to fix the dervish. That is this thread.This thread is about whether or not you think this particular suggestion is at least better than doing nothing.
It's not fill in the blank: The options are A) Yes, I think this is better than leaving the dervish useless, even if it's not my preferred solution, B) No, I'd rather the dervish remain forever useless than for this to be implemented, even if there were no other options, or C) No, because I don't believe dervishes are underpowered (let's leave the reasons out, please; those belong in the other thread I linked to above)