Internet Sales Tax

Just the other day, there were calls on Capitol Hill to revive the debate on an internet sales tax. The Marketplace Equity Act of 2011 has received plenty of scrutiny, and would even fly in the face of a 1992 Supreme Court hearing that declared that state's sales tax can only be applied to companies that physically sell in a state.
Still, the fact remains that states are strapped for money.  And according to the article below, an internet sales tax could generate up to $20 billion for these states.
More over, the National Retail Federation thinks that an internet sales tax would help to counteract the problem of "showrooming" - an actually begin to benefit the Mom and Pop stores as well as the big retailers such as Best Buy.
I find this debate absolutely fascinating, and wonder what it would mean for online companies, which presumably benefit from the government and yet, are exempt from paying it.
I also want to know - how is it determined which state's tax will be levied on a company like Amazon.  Moreover, will some states be more of an "internet tax haven" like Delaware is right now for corporations?
Thoughts?


http://bottomline.nbcnews.com/_news/2012/07/25/12949475-retailers-lawmakers-revive-call-for-internet-sales-tax?lite&__utma=14933801.305116655.1342731935.1343234698.1343242373.17&__utmb=14933801.6.10.1343242373&__utmc=14933801&__utmx=-&__utmz=14933801.1342731935.1.1.utmcsr=(direct)%7Cutmccn=(direct)%7Cutmcmd=(none)%7Cutmcct=/id/26184891/vp/48256089&__utmv=14933801.%7C8=Earned%20By=msnbc%7Ccover=1