Austin launches light rail - is it a good idea?

I've long read about the efforts to promote light rail in US cities and the enormous expense it incurs. I lived in Washington, D.C., and saw how the Metro subway works -and it works. But light rail in Austin? Not so sure.

My neighborhood assiciation had a speaker from Austin Metro touting the launch of light rail in Austin. I also was interested to see Paul Burka (Texas Monthly) on his blog - highlighting the problems with light rail. It's worth a read:
http://www.texasmonthly.com/blogs/burkablog/?p=3046

Is an answer to the commuter's prayers? Is it a good investment? Does it take enough cars off the roads to justify the expense? Or are taxpayers footing the bill for a boondoggle? Time will tell - but it wouldn't be the first time for Austin.