It looks like Hillary Clinton will be the third major candidate, and the first Democrat, to announce her campaign for the White House. From this morning's Washington Post:
Hillary Clinton to announce plans to run for president on Sunday
Hillary Rodham Clinton will formally enter the presidential race with an announcement this weekend, three people familiar with her plans told The Washington Post.
The announcement via social media and a video is planned for Sunday, two of those people said, and Clinton is then expected to travel to the first-in-the-nation caucus state of Iowa early next week for campaign events. Democratic strategists and advisers spoke on condition of anonymity because Clinton has not yet finalized all aspects of her announcement plan.
Clinton is expected to hold mostly small discussion events with voters, foregoing the large rallies and extended announcement speeches of some of her Republican rivals...
Clinton's decision to skip the big campaign-rally announcement speech is interesting, but it's probably way to early to read anything into it (not that many won't try) and try to evaluate what it might mean for her campaign strategy. The most that should probably be said at this point is it seems to repeat her 2008 campaign kickoff, which was delivered through a taped announcement as well.