5.1 is out, so I started hunting the pets for Raiding with Leashes.
Disclaimer: I'm a (currently) ilvl470 Hunter with a long personal history of soloing encounters (mainly as a paladin, but still).
It's certainly doable, but some of the encounter mechanics require a pet if not another person.
- Magmadar, Sulfurion, Golemagg
= You won't need another, but you'll still need to clear Lucifron and the core hound packs for Mags. Otherwise, you can skip all the trash. Just be mindful that that Core Hounds have an annoyingly large aggro radius, even at 60-61.
- Razorgore, Broodlord, Chromaggus
= Easy way: bring someone to help with Razorgore's encounter.
= Very hard way: I was able to solo it, but it took about a half dozen tries. The secret from WoWHead is to drop control of Razorgore as much as you can to draw adds to you. I then aoe'd the ones on me, killed those that were fighting Razorgore, and then ran around the room. Before I re-used the orb, I dropped a fire and snake trap to passively kill adds while I MC'd Razorgore. It was doable, but I only make it by 2-4% less on Razorgore. Not fun.
The rest was easy for me as a hunter. The suppression room was just like watching the beach running scene from Chariots of Fire.
- Prophet, Viscidus, Twin Emps
= Prophet was a fast burn and using my human racial to get out of the MC. If you don't have a pet, you should be fine as well. Kill the mirror images.
= Viscidus was tricky. I looked it up on WoWhead and they recommended (for hunters) the Brunnhildeararaserasdar Bow from those giant icy amazon women in Storm Peaks since it does a tiny amount of frost damage. That's all you need to get the him to start freezing up and then shatter. Basically I just used Barrage once he was frozen and anything with a instant shot capability. He died and I really don't know why he didn't explode, but I'm ok with that. Otherwise, anything that does frost damage will do and those women have the other ice weapons as well. (Note: you need to have done the quest to make them friendly to you, but the weapons can be mailed to others.)
= Twin Emps is very doable as you can outdps their heal; just kill the one that is vulnerable to you. HOWEVER, be sure to clear the guardians in the previous room or you will spend time and energy killing those bozos in the midst of the encounter.
= Loatheb, Maexxna, Gluth
= Loatheb and the Plague Wing are kinda hilarious. Burn down Noth and Helgen (yes, doing the safety dance is still good to save on healing). I did Loatheb without spores for the fun of it, but I imagine it would be much much faster if I took the buff.
= Maexxna is tricky without a pet or other person due to the web wrap. You will need someone to break you out of it. Otherwise, killing Anub and that crazy frenzy chick are trivial.
= Gluth worked for me since I could kite the adds onto me, but it turned into a burn down fest shortly afterwards to prevent him from devouring those zombies. I just let the adds beat on me while I DPS'd Gluth, but you have to be mindful of their stacking debuff. Be sure to clear all the aboms and slimes before aggroing Patchwerk since they will add. Globbius's poison and debuffs still require you to move, but the damage is not scary at all.
Hope this helps. I got *very* lucky and got all my BWL pets in my first go as well as Gluth's bone.