There is an interesting debate ensuing on the message board, USConstitution.net Message Boards « 17th Amendment » concerning the 17th Amendment. I cannot speak with any depth concerning the message board, I am not a member; however there are some interesting and useful links, and the debates seem lively and well ordered. You do however have to register to engage in the debate. Check it out if you have the time.
Update: 19 June 2007; The debate rages on!
Update: 5 July 2007; The thread has been closed by the folks at USConstitution.net. The thread provided some very interesting debate, however, clearly the folks that run the site are decidely for the status quo of a big centralized form of government. still, it is worth your time to read through the postings.