He wouldn't elaboate, but has said in the past he'll make a decision around September -- about the same time the Bush administration promises an assessment on the current "surge" in Iraq. From ABC:
Mr Gingrich has been positioning himself for a possible run, apologizing publically for his affair shortly before his resignation from Congress in 1998 and now on a book tour allowing him plenty of time to talk about a potential run. His criticism of the Bush administration, and his long-time conservative credentials also help him stand out from the crowd of GOP hopefuls -- seen as following the President's war agenda while flip-flopping in their stands on social issues like abortion. (ABC)
Gingrich said as far back as 2003 that Bush had "gone off a cliff" with the Iraq War. Gingrich believes the United States should get out of Iraq as soon as possible.