I just bought Allegiance by Zahn. To me, this novel fills a gap that is largely neglected by most EU authors: interquels between OT films. Prior to this and Zahn's sequel, Choices of One, there are only two prominent interquels (that I can think of at least): Splinter of the Mind's Eye and Shadows of the Empire. I'm aware of the Marvel comics, but those are lower down on the canonicity scale and have been forgotten in many ways. I look forward to reading this book by my favorite Star Wars author and during a period of Star Wars EU that could use some fleshing out.