I'm swiching to my merc as main now.
I love my jugg, but for HM progression its just pointless to try and soldier on. My wonderful guild isn't putting any kind of pressure on us melee players, but when I asked my GM/raidleader if he'd be ok with the swap he was very relieved.
We have just killed Bulo on HM, but as a melee that fight is pretty merciless. To stay safe from carts and lifters you spend so much time running you very rarely get the time to take a few swings at the damn boss. And as soon as they are gone, there are barrels, barrage, and scatters making damn sure you aren't going to be very useful while waiting for a new wave of carts and lifters ^^.
I'm not leaving my jugg because of this fight alone, but as far as 3.0 goes it's a good example of why you just shouldn't bother with melee...