The REALTOR.org site has links to stories that cover these items. For different types of Fannie Mae backed loans there are new underwriting guidelines to help mitigate risk on these loans which means that for the public they’ll be harder to get. Not impossible, but more documentation and stricter guidelines for qualify.
Specifically, Adjustable Rate Mortgage (ARM) loans are addressed with regard to qualifying standards (ie, customers must qualify at the adjusted rate, not the teaser/start rate) and interest only loans (yes, they still exist)now require a minimum 720 FICO credit mid-score.
Happy reading!