There's a new issue of Jim Baen's Universe for April, with new stories from Kevin J. Anderson, Garth Nix, K.D. Wentworth, and others.

Lone Star Stories also has a new issue for April, with stories from Samantha Henderson and others, and poetry from Jo Walton and others.

Clarkesworld's April issue is not yet up, but I expect it will be soon, and it will have two new stories, by Jeff VanderMeer and by Michael De Kler.

Spacesuits and Sixguns has a second issue, with stories from Scott Nicolson, Lucy Snuder, and others.

The on-line reviewzine SF Crowsnest has a new issue for April as well.

Strange Horizons has an update this Monday as well, with a story by Lavie Tidhar, a column about space opera, and an article on the works of David Icke.

SF Revu has put up their April issue, with lots of reviews and several interviews.

Douglas Cohen lists the contents of the upcoming issue of Realms of Fantasy.