After your husband becomes a US citizen, he can file I-130 for you and since the petition is by a US citizen, you do not have to wait for visa quota and can file adjustment of status with the I-130 if you entered the US legally. It would be much faster if he file a new I-130 as a US citizen and you file I-485 along with the new I-130. "Upgrading" a pending I-130 is much more time consuming.
Answered on Jul 23rd, 2011 at 6:46 AM