Apple have rearranged their Mac developer program so that it now costs only $99 and seems to have only one paid variant rather than the three previously available. (Student, Select, Premier). The online only variant is still available and still free of charge.
It appears that this is possibly influenced by the amazing success of the iPhone developer program, which is also $99.
Anything that makes it easier and cheaper for developers to develop applications is probably a good thing. Although obviously you only need this developer program if you need access to pre-releases of Mac OS X and the other benefits it provides. It isn’t now and never has been a required purchase.
They’re still upgrading the sites as I write this, so I haven’t seen all of the details yet, but definitely looking good.
[edited to correct information about the free online program]