Via GOP 12, Mike Huckabee said on Fox News today that he'll make up his mind about running for the presidency in late summer: 

FOX HOST MARTHA MACCALLUM: How and when will you make your decision? HUCKABEE: Much later. Probably in the summer. I'll look at all the options... MACCALLUM: [interrupting] ... why's everybody waiting so long? HUCKABEE: For me, having done this four years ago, I realize that very few people can sustain the burn rate of a campaign if it's going to have to last 18 months. You can't raise and go through that much money and the infrastructure necessary to carry the campaign. The second reason is that, frankly, it's a reason of some illness. I think people get sick of us if we're out there for too long a period of time, and by the time it starts to matter -- when you're getting closer to the caucuses and the primaries -- you've been so, just, essentially, exposed in a campaign mode that there's nothing new. You're the stale loaf of bread on the shelf, and it's very difficult to make your message fresh.

In his new book, A Simple Government, Huckabee hints at making a late entry into the race: 

"As you finish this book (and, I hope, share it with others) I'd encourage you not to get too excited about the "hot" issues and potential candidates that are getting all the attention right now. If you think you know who the personalities and the issues that will be that decide the 2012 election, just remember that four years ago, the "experts" assumed that Rudy Giuliani and Hillary Clinton would be the nominees for their parties and the deciding issue would be the war in Iraq. Who would have thought that John McCain and a guy with a strange name like Barack Obama would joust for the White House and that the main issue would be the economy?"

Most potential GOP candidates, such as Mitt Romney, Newt Gingrich, Tim Pawlenty, Mitch Daniels, and Haley Barbour, have indicated they'll make a decision in the spring.

Mike Pence says he'll decide by the end of January (which is about a week away in case you've lost track), while Sarah Palin has been more vague, saying last month that it will be "some months" until she makes an announcement.