OK, bought myself a few more minutes -- I actually lucked out to pick up the book today myself. My FLGS got the book today, but the UPS shipment was late. If I wasn't held up in abnormal traffic, I would have come and gone before the book arrived.
There's another new core class called the artificier. I havent' read it in detail yet, but it really seems more like an NPC class to me; seems like it would have a hard time contributing anything "on the spot." Of course, if your game plays like a Victoriana A-Team, I guess there's a good use for him...
Also, a Musketeer core class. Obviously a fighter specialized in the use of muskets. Looked good so far. Fair amount of prestige classes, feats and whatnot, and they actually seem flavorful and contribute to the book rather than just being there because, hey, we've gotta have prestige classes and feats. The Oliver Twist analogue was one; the Victorianesque big game hunter is one ("Dr. Livingstone I presume?") an arcane arealist that seems a bit Red Baron-like is one. Did I mention they defined the source material fairly broadly? This makes the book much more useful though.
There's a lot of info in the first chapter on what steampunk is -- although they essentially lump scientific romance of H.G. Wells and Jules Verne as steampunk, including how to gradually introduce elements of it into a standard D&D campaign, or how to build one up from scratch. These ideas rocked, and I found myself thinking of even using them someday (although I've already been working on a steampunk-fantasy setting for a while).
Also, the first credited author is Mark Chance -- any relation to the Mark Chance we know from around here, I wonder?