This seems like a pretty big deal for a lot of startups. The compliance requirements alone sound like a nightmare. I'm curious why none of the recent articles submitted to HN (from very legit sources like NYT and WSJ) are getting upvotes. Also, it's not like this is a hypothetical - it looks like it's going to be railroaded through very quickly.
EDIT: Here are some links:
http://www.nytimes.com/2013/04/23/technology/internet-sales-tax-gains-ground-in-senate.html
http://online.wsj.com/article_email/SB10001424127887324493704578432961601644942-lMyQjAxMTAzMDIwMTEyNDEyWj.html
http://thehill.com/blogs/hillicon-valley/technology/295431-internet-sales-tax-advances-after-obama-endorsement-
http://www.realclearpolitics.com/video/2013/04/22/carney_internet_sales_tax_is_simply_about_leveling_the_playing_field.html