Comic News I has IDW's March 2009 solicitations with blurbs and covers for both of these issues. It also has a blurb on the AtS: ATF HC #3 relaese too - but no cover.
Blurb:
Angel: Blood and Trenches #1
John Byrne (w & a & c)
In Europe, war ravages nations, but a greater darkness than human conflict calls Angel back across the ocean from his distant home in America - bodies of combatants found drained of blood, and signs of an ancient evil once more abroad in the world. Writer/artist John Byrne tells an untold tale of Angel's WWI exploits!
Blood and Trenches #1 Cover:

Blurb:
"Angel #19
Kelley Armstrong (w) Dave Ross (a) Gabriel Rodriguez, Nick Runge (c)
As Angel and the remaining survivors from their sojourn to Hell attempt to rebuild their lives and find purpose once again, they must also contend with the threat of a vengeful Lord, a mysterious cat-changer and a winged being from beyond ..."
AtS #19 cover: I wonder if all the reporters and photographers tie in with the BtVS S8 #21 (20? 22?) events?

Blurb (and only blurb, no cover shown):
"Angel: After the Fall, Vol. 3 HC
Joss Whedon, Brian Lynch (plot) Lynch (w) Nick Runge, Stephen Mooney (a) Alex Garner (c)
Angel's After The Fall storyline is back in the crosshairs in this third hardcover volume of the latest Angel series! Long-time friends-turned-enemies Angel and Gunn are on a collision course with destruction, and when Gunn's master plans get exposed, well, let's just say things get chippy. But as usual, the problem everyone expects turns out to be the least of their concerns! Experience all the action, drama, deception and demonic humor you've come to expect from Brian Lynch (Spike: Shadow Puppets), joined this time with artists Nick Runge and Stephen Mooney in the exciting continuation of Angel: After The Fall!"
Blurb:
Angel: Blood and Trenches #1
John Byrne (w & a & c)
In Europe, war ravages nations, but a greater darkness than human conflict calls Angel back across the ocean from his distant home in America - bodies of combatants found drained of blood, and signs of an ancient evil once more abroad in the world. Writer/artist John Byrne tells an untold tale of Angel's WWI exploits!
Blood and Trenches #1 Cover:

Blurb:
"Angel #19
Kelley Armstrong (w) Dave Ross (a) Gabriel Rodriguez, Nick Runge (c)
As Angel and the remaining survivors from their sojourn to Hell attempt to rebuild their lives and find purpose once again, they must also contend with the threat of a vengeful Lord, a mysterious cat-changer and a winged being from beyond ..."
AtS #19 cover: I wonder if all the reporters and photographers tie in with the BtVS S8 #21 (20? 22?) events?

Blurb (and only blurb, no cover shown):
"Angel: After the Fall, Vol. 3 HC
Joss Whedon, Brian Lynch (plot) Lynch (w) Nick Runge, Stephen Mooney (a) Alex Garner (c)
Angel's After The Fall storyline is back in the crosshairs in this third hardcover volume of the latest Angel series! Long-time friends-turned-enemies Angel and Gunn are on a collision course with destruction, and when Gunn's master plans get exposed, well, let's just say things get chippy. But as usual, the problem everyone expects turns out to be the least of their concerns! Experience all the action, drama, deception and demonic humor you've come to expect from Brian Lynch (Spike: Shadow Puppets), joined this time with artists Nick Runge and Stephen Mooney in the exciting continuation of Angel: After The Fall!"