Here's my 2 cents:
Babies aren't really good walkers or runners until they've had lots of practice. I'm sure that in their little heads, they probably can't understand how people do that walking thing. Most of the time, they fall down a lot while learning to walk, but eventually they get the hang of it once their little muscles get conditioned. Just think that you're taking little baby steps every time you attempt a workout -- and eventually, if you stick with it, you'll be running through the workouts like a pro.
Secondly: The way I see it, if these ladies can do this workout, and the gym is "packed to capacity on Wednesday morning" as one of the new workout's descriptions stated (meaning that all those people can do the workouts, too), then why can't I?
The other thing I do when a workout gets too tough for me, ...I take a break. I am asthmatic, and let's face it - I'm not as young as I used to be, so getting through some of these routines is going to be tough for me and it will take longer for my body to get used to the them. So, I do what I can do, and rest when I need to. I eventually build up to a routine (it took me almost 2 months to be able to get through Cardio Blast without stopping or messing up the routine; and the other day, I did a couple of more advanced and intricate ab exercises that I thought I would NEVER be able to do. I still can't do planks with one arm and one leg extended, but I'm getting there!)
So, don't give up. Stick with it. Be positive - you can you can you can you can you can you can!