I'm not sure about music, I haven't gotten any on mine yet, but you can definitely run multiple apps at once, and they do keep running when you switch to another one.
I ordered an Ipad 2 so in a month I'll enjoy talking about it in this thread. The first thing my mother asked me when I told her I was buying one was if I was spending all that money just to read comics on it. I said no...but the answer was pretty much yes.
I downloaded Flipboard last night. It takes numerous feeds from websites, blogs, facebook, twitter, etc and turns them into a magazine tailored for you. It's pretty awesome how it presents everything, too. Very slick.
I just watched a video on that. That's a use of social media and modern technology that makes a lot of sense. The fact that it looks so slick is just gravy.
I picked up a viewsonic g tablet for 180 bucks a few days ago. Out the box, it was pure ass, but after a overclock and new rom, its flying and this thing is great. Viewing angles arent great AT ALL but I like the degree of privacy it gives me.