I guess the 30-second speech version would be something like this:
"The Pathfinder RPG is basically the same game you already know how to play, but we've tightened up some rules and made the base classes more appealing all the way to 20th level, and added in a lot of new options in feats while streamlining skills. The overall hope was to avoid cutting as much as we could from 3.5 while adding new options where we could—but in the end, it should still play well with your current collection of 3.5 gaming material."
I wouldn't say the Beta's 90% locked in at all, especially since the print version's missing prestige classes, a lot of spells and magic items and feats. and any flavor text. The final version'll add that all in, and some of the class mechanics may change as well (barbarian rage and wild shape are two that we're really looking at). But the Beta's still a great way to get a preview of where we're going. Again: We try not to cut too much out, but add stuff where we can. We've made a LOT of changes to the sorcerer, for example, but you can still play a 3.0/3.5 style sorcerer if you want; that's still an option. It's just no longer the ONLY option.
Beyond that, yeah; the things we're focusing on from now till we ship to the printer is clearing up language, adding flavor, dealing with power creep, etc.
As for what criteria we use to decide what goes in and what doesn't? For one, we'll be looking at the playtest feedback; if something is universally hated in playtest, it has a good chance of going away. If something is super popular, it has a good chance of staying.
But the playtest is only one tool we're using. We're also using our own collective experience with the game as well, as well as relying on other great designers like Monte Cook for advice as well. But when it comes down to the final stage of the game, and we're making the decisions on how many familiars to add... that decision is pretty much up to Jason. I have veto power, as does Erik Mona and Lisa Stevens, but for the most part the four of us are pretty in sync with where we want to go with the game. So it's basically four of us making those final decisions, with the bulk of that decision making being Jason's job. And of course... he weighs his personal experience with the game, the rest of our experience, advice from Monte, findings from the playtest, and feedback from Paizo's customers from the last six years or so as well to inform those decisions.
I'm pretty confident the game's in good hands, in other words. But I still have my fingers crossed!
