Effective today, the US Postal Service will be raising rates again. Luckily they're not as drastic as last year, but there are some significant changes. Etsy has put together a pretty good graph of the most effected areas for domestic and international shipping changes.
The rates that I'm seeing the most significant changes to are stamps themselves, going from 46 cents to 49 cents. And 1-3 oz First Class Packages going from $1.69 to $1.93. Small flat rate boxes will also go up 10 cents.
Luckily Etsy makes it very easy for sellers to make changes to their shipping profiles. On the left hand side of the page there is a category labeled Shipping Profiles. From there, you will see all the profiles you have created. On the right hand side there is a place to edit your profiles.
Once you click edit, you can make the necessary changes to your profile and edit all of your listings in this shipping profile at once.