The new Bakes on Mesh viewer is now live (if you use the official SL viewer). Those of us who use a third-party viewer will have to wait until an update is released. So those who are already using BoM will probably look strange to us until then.
There are several really good blog posts out there already about how to use BoM, but what it essentially boils down to is the ability to use system layers (remember those?!) for skins, tattoos, makeup, clothing, etc. – even with your mesh body. I’m not going to explain it all here in detail (for that, you can read more here, here, and here). I haven’t actually tried BoM myself yet, so I don’t want to hand out bad information.
If you use a SLink body, an update for use with BoM is available. I haven’t yet heard about update for any other bodies or heads, so we will have to wait for those creators to update. I’ve used my Maitreya body for so long that I don’t think I even have other mesh items anymore, so I really hope it gets updated. If it doesn’t, I may have to switch over to SLink. I did keep my SLink hands and feet (and shoes!), so I’ll have to wait and see what happens.
There are some issues with BoM, so don’t expect it to work perfectly right out of the box. Hands and feet are known to cause issues, so I’m hoping that by the time Firestorm updates for BoM, most of the bugs will have been worked out. Fingers crossed!