I don't think you have to worry about PayPal going away any time soon, Jennifer. With the amount of accounts they have and the tie to eBay, I think they'll be around a long, long time.
As for a plausible alternative, I really don't think there are any that have the kind of professional as PayPal (no, they didn't pay me to say that

). E-Gold is OK, but I've heard of people having trouble with them too.
I think that with the amount of business that PayPal does, the horror stories you hear about are such a tiny minority that any business would have those kind of things. For example, I do a fair amount of business via PayPal and I've never had any kind of problem, but I know of people who have. Sometimes it's due to a misunderstanding and sometimes it's something that PayPal just won't do, but I've never known anyone who had their account frozen as long as they followed the TOS.
I'm not saying PayPal is perfect, but if you're a small business or a one-person empire, I still think it's best at the price. Just IMHO of course.