Part of the pitch for Fable has been it's emphasis on what D&D players would call alignment issues. If you are good, you wind up with a halo and protective spells. If you make evil choices, you grow horns and your spell options are creepier. On the whole, this alignment system was better integrated into the game than the equivalent system in KOTOR; the game didn't stop dead in the water every time there was a moral choice to be made. There's also a renown system, which allows you to be a publicity hound in the best LJ attention-seeking tradition. These are interesting systems from a design perspective, but have relatively little effect on gameplay Guards and villagers care about your heroic/villainous status and your looks, but the main storyline isn't played out in the settlements. Only two quests I encountered took place in the cities. In other words, this part of the design doesn't matter to players who really just want to explore or power-up.
So if you like, you can ignore all that and spend your time courting the ladies (or the men, for that matter). There's a social system of expressions such a flirting and posing and bowing and so forth. You can get married, be a landlord, trade goods between towns, wander off in a million directions that RPG fans will appreciate. Part of the game is what you make of it. Again, all very nice, but I suspect the players who really love that stuff are busy crafting in EQ, trading in WoW, or running dance macros in Galaxies. The big MMORG are investing a lot of effort in non-combat activities, and frankly it doesn't feel as if it matters that much when you pursue some of these activities alone, rather than in a social game with other people.
Anyway, I'm a little more of a goal-oriented player than that. At its heart, Fable is a mainstream fantasy RPG that follows a completely standard rescue-and-revenge plotline. The story is well-executed, the graphics are very good, and the art direction leans in the direction of Nintendo-like childishness rather than gritty Doom 3 darkness. You start the game out as a young boy, and over the course of about 11 hours if you only pursue the main narrative (or 40 hours if you follow every side quest) you grow up into either a weedy wizard, a roguish archer, or a beefy fighter. In other words, you can play this as a hack-and-slash game, a stealth game a la Thief, or a game of arcane prowess.
I stuck to the melee fighter type, stayed heroic, and bought or kept the "shining armor" every chance I got. No tattoos, and only good-looking haircuts. I was quite pleased with how the character turned out. In one sense, the "actions determine appearance" system of the game means that the whole game is one long bout of character generation. If they're smart about Fable 2, they'll allow you to import your previous character's looks off the hard drive.
Minor gripes: Inventory management was a little awkward, but combat was amazingly smooth. Some of the side quests implied alignment changes that didn't always seem to apply. And the system for ordering NPCs around required remapping of some of the defaults. Load times are long by XBox standards, but short by, say, Vice City standards.
The machinima people would go absolutely nuts for the Fable protagonist --- he's extremely controllable in appearance and has a wide range of triggered emotions and social actions. Unfortunately, for proper machinima, the game would have to support at least co-op and ideally multiplayer. Fable is, however, also a throwback to the days before every worthwhile game had a multiplayer, online component. I enjoyed the single player game, but I did wonder what it would be like to play in co-op or HTH modes.
Back to that 11 hour timetable. You can finish Fable twice in a weekend. That briefness is one of the blackest marks against it, despite the general trend in the industry toward shorter games. You can literally play it through as a rental, which is no longer such a rarity in RPGs as you might suppose. At the end, I wanted more. Which would have been a good thing, except that the game railroads you once you enter the final quest sequence. That works cinematically. After defeating the Big Bad, you can keep playing if you watch the credits. Who wants to play after the finale? Not me.
As an example of current RPG tech, Fable attempts some interesting subsystems that have long been staples of paper RPGs, but that have not previously made a good appearance on computer RPGs. Its design is miles ahead of the number-crunching, skill-tweaking madness of many titles, or the endless "plot coupon" collecting of the lamest RPG storylines, and may even expand the RPG audience a little. The environments are small but effective, and the sense of immersion is very high due to a strong musical score, a smooth framerate except in the most crowded conditions. This is a quality game that takes some risks, but ultimately does not reinvent the genre or abandon most RPG conventions. If my expectations hadn't been so high to begin with, I might have raved more about its successes. As it is:
Recommended. Play it, love it, move on.