I really wasn't that impressed with the B5 book. I liked the way that telepathy worked, but I didn't think that the starship rules were laid out well enough for me to use them in a campaign, and the character classes did not wow me.
I'd rather see a future version use d20 Modern or Future, and just have PPGs do 2d10 damage so that massive damage is a real concern any time a shot connects.
The Season One episode guide was excellent, though, and I liked the way they created plot hooks for each episode.
I'm likely biased, though, because I'm a dedicated homebrewer -- I'd be using the book to make my own space opera campaign, so while I appreciated the episode guides and plothooks, and I did like the show a ton, I didn't have as much right-out-of-book use for the stuff as other people might.