Originally slated for a December 15th release, it has been pushed back to December 29th.
Marvel.com has adjusted accordingly on their site.
Be sure to pick up your copy of issue 4 at your local comic shop, and help make the demand for this rising comic to shine through once again. This issue will be a perfect jumping on point as one story arc ends and another begins. So if you're afraid you missed too much already, fear not, you can still easily catch up.
The January solicit hasn't changed though, so issue 5 is still slated for January 19th.