I found a How-To channel for solo'ing old raid bosses on a Hunter. It also includes how to exploit the first boss in BWL so you can do the boss solo, and how to create your own raid using a lvl 1 alt.
Steevnash Hunter - YouTube
Hopefully this isn't a little narrow reaching for this forum. With 6-7 weeks left of Cataclysm it's still incredibly useful information I think, even if your main isn't a hunter... roll one/gear one and farm mounts/money the last few weeks of Cata and let it account spread once MoP hits back to your main.
As I'm sure many have noticed, come MoP Blizzard is nerfing the amount of money that raid bosses drop. Pretty much the entire reason for this is because of how fast Hunters can solo old raid content. Until that time it's still very possible to make 2-3k/hour farming these. As well as transmog gear for anyone you want to bring along with. It's difficult to make a ton of money from this as you can only do the raids once a week, but farming the Mini-bosses from ZG is very profitable as well as it's clear able in less than 10 minutes and you can reset it for the usual 5 clears an hour.
Solo'ing isn't just a way to get some fast cash, it's also a great way to farm some of the most exclusive mounts in the game. No more looking or joining a raid only to see a raid mount drop and then you have to roll against everyone else for it. If it drops its yours.
As long as you get yourself into gear between 378-384 ilvl just about every encounter you see is doable, if you have an alt hunter that ilvl is reachable within the first night of hitting 85 if you want.
Some specific links below:
Exploit Razorgore encounter
Create raid with a lvl 1 alt
Solo ZG mini-bosses for up to 2k gold/hour
2 Million XP in under 3 Minutes in MoP
The Hunter and Pet spec I would recommend for solo'ing is this:
Hunter
Pet
A lot of solo'ing is about the ability to really burst down a boss very quickly inside of burn phases. This can be very simple for a seasoned hunter, but someone that is playing an alt might not know the ins and outs which would make solo'ing the harder bosses a little more frustrating. If that is the case there is a video about how to play the MM spec here:
Marksmanship Basics for Hunters in 4.3
Don't hesitate to ask if you have a question about any of the encounters.