Yes he is, although he's not a main character and its not told by him. They mention him and he's still there, but he's not telling the story.
It is the 2 installment in the heros of Olympus series
fall 2013
05.05.2012.
The Lost Hero
Leo Valdez dies in "The Blood of Olympus," the final book in the Heroes of Olympus series. Piper McLean does not die in the series.
The third book has been announced as the Mark of Athena. The book is tied to Annabeth.
I heard that there's supposed to be 5 books, like Percy Jackson.
A sequel of The Percy Jackson series is coming out in october called The Heros of Olympus.
The Last Olympian was the last Percy Jackson book in the series, and is the last book from Percy's point of view, but he will still be a character in The Lost Hero (Heros of Olympus), which is told from third person... Well, at least, that's what I think. But the next book in the Heros of Olympus series which is going to be The Son of Neptune (I think), there will probably be more of Percy than Jason... But correct me if I'm wrong because I didn't read TLH yet ;)
No. The Roman Camp only comes up in the new series, Heros of Olympus.
The heros of Olympus includes Percy Jackson and some new characters