Not even counting Miracle as an analog of Wish, I count 5 spells on the 9th level Cleric list that aren't on the Wizard list. Which ones are defining features of the Cleric class-- just the healing and resurrecting?
I'm not exactly sure why you're asking that question, but why not reverse it? Wizards get quite a few spells that aren't on the cleric list (17, to be exact). Clerics are arguably powerful enough, and giving them access to wizard spells as well would be a bit much, IMO.
I find it interesting how the arrival of 4E and the announcement of Pathfinder motivates people to _really_ look into the problematic issues and not just post stuff intended as a mere house-rule, but actually consider ways to publish them. You guys should have been active 4-6 years ago (perhaps before 3.5 was in the works!)
As has been pointed out, some of us
have been around since before 3.5 came out. The fact that WotC's stopped support of 3.5 is what has really allowed us to mess with larger rules issues (like the skill system) than modular bits and pieces like crafting, turning, and base classes. I can't speak for anyone else here, but only the (very likely) probability of a future Wizards release invalidating any work I've done prevented me from doing large-scale revisions before.
Since the Paizo is trying to make core classes that will steer people fropm multiclassing...
It's not to discourage multiclassing so much as to
encourage staying in a single class longer. Rampant multiclassing is usually the result of base classes having no features (or none worth taking), so the player chooses levels in another class for the desired features or because it fits the concept. With base classes having more features and being more clearly defined, it makes it more likely that players will be able to develop their PC within the scope of that class alone instead of a mix of umpteen different classes.
Getting on to the discussion at hand... if I'm understanding this right, all spell slots will just go into a big pool and you choose what spells you want from a given class list (assuming you're high enough level)? I think it could work (especially with the restrictions), but unfortunately for me, it invalidates the changes I made to the sorcerer - I gave sorcerers the ability to learn and cast any spell from any list, though they keep their spells known/per day. It greatly enhances what kind of sorcerer you want to play without seriously increasing their power, and makes them completely unique from wizards.