For most folks this is probably old news, but I just recently found it and I'm excited, so here goes...
One aspect of pre-4E d20 games that has started irritating me lately is the amount of time it takes to create NPCs and monsters. They follow all of the rules that characters do, so it takes a while. It never bothered me before the new edition, but after DMing a 4E campaign and now returning to D20 Modern/D&D 3.5 rules, it has become frustrating.
Enter the Pathfinder Beta
I've had this pdf sitting in my hard drive since before Christmas, but I never spent much time reading over it because so much of it feels like it has just been copied & pasted from 3.5, a system that I'm familiar with. That said, in a moment of boredom, I opened the file again and flipped to a random page... and struck gold. I absolutely love pages 292-298. Basically, it's the Pathfinder version of the "designing your own monster" section from the 4th Edition Dungeon Masters Guide, complete with stats by challenge rating.
Now, it isn't perfect. The damage columns only give a number (average damage) rather than a dice range, but that shortcoming can be overlooked. I can still throw together a quick NPC in a quarter of the time it used to take. I still intend to go through the whole process for important NPCs, or at least the ones that intrigue me. But this is an excellent tool for the ill-prepared dungeon master.
Now I need to figure out if there's a similar (or better) version of these tables in the final version of the Pathfinder core book. If there is, I might blow the cash for the book just for this section... it's that useful.