I guess Pathfinder is a good gauge for what constitutes "different enough." I did not pick up the PF core book when it was first released though I played in a few games and ran the Free RPG Day adventures prior to this year (though I ran them using 3.5E). About a month ago a long time gaming group in the area asked me to jump behind the screen for their PF game because their regular GM was moving out of town. I've grabbed the core PF PDF, some monster cards off the PFSRD site, and have been spending time using that site and the PDF to bring myself up to speed, It seems significantly different. Of course, if WotC was going to build off the 3.5E engine rather than the 4E engine (which is even more removed already from 3.5 than PF, as anyone would agree), they'd either have to go in whole new directions or just build on the PF engine. I don't expect we will see that.
One way to build off the previous engine that I have experimented with is to focus more on RPGing during charatcer creation. I've often heard people compare any contemporary RPG that uses or makes provisions to use minis as drifting from the realm of RPGs into the combat minis games territory, along the lines of DDM with only a vaneer of RPGing tacked on. I've seen it, certainly, at gamestores, gamedays and conventions. Even in discussions with folks who were involved and who agree with what I poiint out as having been the manner in which they play, they will flat out say that the way they play the RPG is RPGing. Personally, one combat after another, after another with the only characterization being that one player tells another to watch his back. I swear I watched a three hour combat game, played using RPG rules, where this was absololutely the only thing even approaching RPing. A bystander might even argue that it was the player not the character but let's leave well enough alone. Some folks claim the problem lies in the heavy fcus on combat rules, often making up the bulk of the rules in any RPG system. I think it begins earlier than that in how character creation is presented and how it functions. I think there are ways to fix that that do not focus on core mechanics so much as on presentation and characerization. These articles don't make me believe they understand the spirit of RPGs let alone how to fix what they seem to now believe they have broken.
Eh, I don't think I buy this. There's plenty of 'fluff' attached to classes and races in the PHBs. There are also quite a few other RP hooks. More than in past editions from what I can see. People may get distracted by the shiny combat game and NOT RP, but I don't think the presentation of 4e discourages it at all. I think there are a few factors that have converged to create the 'people don't RP in 4e' trope. At some level WotC did it, but I think the story is not very straightforward.
1) They made a decision not to build a lot of adventures and in-depth settings. The system, particularly early on, was very heavy on crunch books. The adventures they did make were railroady hack-fests. None of this really helped.
2) Combat is always long and involved. I'm not sure I like the term 'too long', but it sucks up time and if you have players that like to fight you do quickly run out of time to get them RPing much. There are answers to this however, the DMG simply should have said more about it (I'd say they didn't understand the issue at that time though).
3) The encyclopedic rule system tends to discourage a lot of tinkering, or more importantly a lot of experimentation with story related game elements. An example would be cursed items. Usually they're problematic, so they aren't discussed in the rules, yet they are a perfectly viable tool to use. Most DMs simply avoid them because there is almost nothing 'official' on the subject.
There are a few other things in the same vein, but I'd also say that IME 4e allows for some exceptionally rich RP opportunities as the PCs have a hard time falling back on 'fixer magic' to deal with plot issues and such. Rituals, diseases (curses fall here), a good solid non-combat XP system, and the fact that the party will generally cover most non-combat capabilities pretty well actually makes doing this stuff quite easy and rewarding.
The genuine ease of building good monsters and opponents helps a LOT too. Being let loose from the old "well, lets see what magic user spell we can pound into this round hole" is good. Rituals again are a great boon here as they have no impact on opponent's combat capability (in general) but provide nice plot devices. Unlike AD&D where monsters were really SO different from PCs that it was hard to apply PC mechanics to them in 4e they have all the sorts of hooks that PCs do, so it is actually quite easy to borrow PC mechanics of almost any sort for them as well.
Thanks for the reply AbdulHazred. I agree the bonuses were potent in the context of the system. My only point was the numbers themselves were more contained than you had in d20 (wasn't thinking of 4E so much as 3E with modifiers going into the double digits routinely). Personally I prefered the more contained bonuses.
Yeah, I understand what you mean. There were certain characteristics of the way that worked. One was that generally a stat between say 8 and 14 didn't really matter. It COULD matter for ability checks, but IME those were actually used pretty rarely (but I'm sure that isn't everone's experience). One result was a character that was 'blessed' with all mediocre stats was pretty blah and they all tended to blur together after a while as 'Joe Anycharacter'. So in a sense I kind of like the fact that a 14 is materially better than a 12. OTOH the range from +1 to +4 is a pretty significant difference in to-hit (less so for skills, but it certainly matters there too). Add in the fact that characters ramp right on up to +8 or +9 at high epic and I agree that stat bonuses are a little steep. I'd ditch stat boosts myself, which would help.