The funnyman proposed to The Devil Wears Prada actress in August (09) after a whirlwind 10-month romance.
The happy couple has been busy preparing for their wedding - and E! News claims they're planning a May (10) ceremony.
A source tells the website, "(The wedding will be in) about a month. She is planning the wedding right now and is down to the last-minute details. They picked up their wedding bands yesterday."
The insider also revealed it will be "a big wedding…probably in London or Los Angeles".