Amusing discoveries
Apparently, Paizo has recently published Pathfinder, effectively D&D 3.75E. The conversation documents were available for free, and they detailed most of the changes from 3.5--mostly increasing the power level of the core classes; standardizing races; simplifying some skills and combat manuvers; and overhauling protection, instant kill/disable, and polymorph spells. It looks like they also put some effort into balancing very low/moderately high-level play with the "golden levels" of 3.5, though I can't tell how well that works without playtesting.

They also say that 3.5 material, particularly monsters, are compatible with Pathfinder. I would suspect that a Pathfinder Fighter and a Tomb of Battle character could stand side-by-side, at least power-wise, without any major conversions, but you'd need to basically toss out the CR system in favor of Pathfinder's new XP system, because both of those classes totally out-do the 3.5 core Fighter, and can easily handle bigger threats.

I give them a lot of credit for catering to the "4E sucks!" portion of the market. Now, if I wrote a rulebook for the AD&D "2.75E" rules I'm using now...

Edit: There's a Pathfinder SRD, which allows me to look at the spellcasting changes in more detail. I like what they've done with the polymorph subschool quite a lot.