It looks like the uproar over Congress’s online-piracy bills is having a real impact. This weekend, the White House strongly hinted that it would oppose the current legislation. And key sponsors are edging away from the bills’ most controversial features.

It’s also a sign that momentum on online-piracy legislation is shifting dramatically. Just six months ago, these bills seemed all but inevitable. The Senate version of SOPA, the Protect IP Act, was being held up by one lonely senator, Ron Wyden, and most of the bill’s backers were confident of eventual passage. But critics and tech exports started pointing out that these bills could impinge on free speech and disrupt the workings of the Internet. Online communities like Tumblr and Reddit organized loud, boisterous, and often clever campaigns — the document-sharing site Scribd, for instance, made a billion pages vanish to protest the bill — and public opinion swung sharply. A Reddit campaign managed to persuade Paul Ryan to oppose the bill, for instance.

As a result, even the most ardent backers of the bill are now softening their support. Sen. Pat Leahy, a key sponsor of the Protect IP Act, has conceded that more study is needed for the provisions that would allow rogue sites to be delisted from the Domain Name Service (basically the Internet’s phone directory). Critics have warned that mucking with DNS could splinter the architecture of the Internet.

In the House, meanwhile, SOPA sponsor Lamar Smith (R-Tex.) has said he’d remove the DNS-blocking provisions from his bill outright, pending further review. And last week, six Republican senators on the Judiciary Committee also wrote a letter to Senate Majority Leader Harry Reid asking for more time to study the Protect IP Act. (It’s currently slated for consideration Jan. 24.)

Now, that doesn’t mean these bills, or their most controversial features, are dead and buried. Leahy, for one, was pretty clear that still supports passing a bill with DNS-blocking — he just thinks that feature should be studied carefully before it actually gets implemented. (As TechDirt’s Michael Masnick points out, that sounds like a compelling reason to slow down and reconsider before passing the bill, rather than enacting a provision that lawmakers don’t fully understand.)

Still, the momentum does seem to be shifting. Reddit and Wikipedia are planning to go dark this Wednesday in an attempt to raise awarenesss and put even more pressure on lawmakers. Right now, the main alternative to SOPA and Protect IP is a bill backed by Wyden and Rep. Darrell Issa (R-Calif.) that would focus on curbing the flow of money to foreign sites dedicated to copyright infringement, but would be considerably narrower. You can read about the pros and cons of that bill here.

Related: Everything you need to know about SOPA, in one post.