Here are some conclusions I've drawn from various aspects of the recent MoA cover and full first chapter release as well as the blurb for the MoA and the prophecies.

I checked Rick Riordan's blog at 1 am on Saturday, but nothing was up, so I went to bed. SpringFling and I stayed up until 1:45 talking about random stuff, and then we went to sleep. At 9:30 when her dad came to get SpringFling and I had finished my cereal, I went to the computer and began my science homework. And opened up Rick Riordan's blog. It just finished loading, but I saw something red on it, so I slammed the top shut and breathed for a while, shaking. Then I opened it a tiny bit, just so that I could navigate to change tabs by only looking at the reflection on the keyboard area place. Once I did that, I had to wait an hour before I thought I'd calmed down enough. I changed tabs...and had to bite my had so that I wouldn't scream...IT WAS THE COVER FOR MoA! (see my profile pic)

It's exactly like I dreamed it would be! Scary thought...

Chapter: Athena gave Annabeth 'the worst gift she'd ever gotten', which is the mark of Athena. This could supposedly be an object (as it says that something is in her pocket), and the orders from Athena for Annabeth to avenge her. I think that means that Athena wants Annabeth to take revenge on the Romans for something they did to her, or there's someone that Annabeth's going to meet who she has to kill. Also, I think that the mark was given to her on her birthday, which would therefore be in May because the 'gift' was given to her a month before, and the month is June.

"In a fantastical ship called the Argo II, seven demigods journey by air across the United States and by sea to Rome on their quest to defeat the earth mother, Gaea. Meanwhile, war is breaking out between the Roman and Greek demigods they left behind, and only Annabeth holds the key to restoring peace." "In her pocket Annabeth carries a gift from her mother that came with an unnerving demand: Follow the Mark of Athena. Avenge me."

Based on the blurb, I've gathered that there's still going to be bad blood between the Romans and Greeks with Octavian leading Camp Jupiter against Camp Half- blood, which could be led by Clarisse.

Based on the cover, I think Jason and Percy are going to have HUGE personality clash issues, which will lead to a battle between the two, or possibly Gaia turns one of them against the other (I think she's more likely to influence Jason, because power isn't very important to Percy). But what I find the most odd about the cover is the owl. I get that it represents Athena, but what about it's eyes? One is narrowed more (the one on Percy's side of the cover), so I'm thinking that maybe Athena is rooting on Jason in that fight? Or maybe the look is just that inquisitive look Annabeth and Athena give that makes you think they're analyzing you all the time.

Based on the prophecies:

Seven half-bloods will answer the call,

Obvious: Jason, Piper, Leo, Frank, Hazel, Percy, and Annabeth

To storm or fire the world would fall.

This might relate to the cover: Jason and Percy fighting, but I'm not sure what the fire would be... the background IS red, though...

An oath to keep with a final breath,

Maybe it's Percy's oath to fight with the Romans, should the Greeks attack, or it might refer to Athena's order for Annabeth to avenge her.

And foes bear arms to the doors of death.

Again, obvious: Gaia is able to control the doors of death, but ever since the SoN, we also know that Nico is being kept at the doors of death, and the demigods will have to close them to have any hope in destroying Gaia.

Wisdom's child walks alone

I'm very sure that 'wisdom's child' refers to Annabeth, and I'm thinking that maybe the 'walks alone' part means that she makes some bad decision to do something (as she says in the first chapter of MoA: "...she thought she could hear the presence laughing, as if it was delighted by the bad choices she was making." [page 11]) and by doing so, ends up going through something alone. It could also mean that Annabeth will be the only one to read the signs to the doors of death, and in doing so is alone in it, but I don't think that's very likely. Another interpretation of the line ties in with the blurb. Maybe Annabeth 'walks alone' by trying to keep peace between the two camps.

The mark of Athena burns through Rome

Well, obviously the characters go to Rome, and maybe 'The mark of Athena' refers to the thing that's in Annabeth's pocket. if so, then somehow that object 'burns through Rome'. Then again, it may not even be an object. SpringFling pointed this out the other day. She reminded me that Pandora's pithos held not objects, but diseases and many things awful. So maybe the mark of Athena is something like that, but it gets free from Annabeth's pocket and the object is loose throughout Rome.

PERCY is confused.
JASON has a problem.
PIPER has a secret.
LEO has a way with tools.
HAZEL is supposed to be dead.
FRANK is a klutz.
ANNABETH is terrified.

Percy–I think he's confused about the whole "Wisdom's daughter walks alone/The mark of Athena burns through Rome" and he's also confused about what Hera said to him, about how Annabeth will be causing him trouble.
Jason–I'll bet the problem is that Jason and Piper are boyfriend/girlfriend (OFFICIALLY! YES!), but Reyna still kind of likes Jason, and he possibly likes her back. (Though hopefully not, because I root for Jasper and Leyna.)
Piper–Maybe the secret is who her father is...but I don't think so. I can't even put my finger on what the secret is!
Leo–Well, DUH! Son of Hephaestus! Fire-user!
Hazel–Once again–DUH!
Frank–Yes, yes he is.
Annabeth–...of the mark of Athena. I never thought we'd see Annabeth terrified of something besides spiders.