If you have a free account, many things are off-limit to you. you need a Select ($500/year) or Premiere ($3500/year) account to get access to the Panther betas and ADC TV, among other things. I think $500/year is a bargain for an ADC Hardware Discount (20% discount off of any computer at the apple store once a year) and access to ADC TV and beta software, among other developer resources. There is also a student membership if you're in college, which is $99 a year, but i'm not sure what exactly that gets you besides a once-in-a-lifetime ADC Hardware discount.
you can compare the different types of membership
here.