Wulf Ratbane said:
You need to be able to strike the dragon. You need to be able to strike the incorporeal, flying, armor-bypassing, level-draining spectre, and according to mearls, you will to be able to do it in such a way that the spectre remains CR7. The spectre will be a cakewalk for four 7th level Iron Lore heroes.
Well, pulp heroes like Conan and the Grey Mouser have had to deal with foes not of flesh and blood. How do they do it? I recall one Solomon Kane story where he overcomes a spectral foe by galvanizing himself with sheer force of will. Sometimes it's with the timely aid of a priest or hedge wizard, so perhaps this is the role of the Arcanist class within the party.
If he doesn't "fix" the dragon's ability to fly (as just the easiest of examples), then the dragon will still prove too difficult for its CR. If the dragon is able to retreat to the skies until its breath weapon is ready to go again, he will crush the PCs. They can't bypass its DR (a system element mearls has already said he has not changed), they have no magic weapons, they have no magic healing, and they can't fly.
I'm no apologist for Mearls, but you do seem to be focusing on a few of Mearls' broad statements as if they were much more specific comments than they were intended to be. He didn't say, for instance, that characters would be utterly without a way to bypass DR, he merely confirmed that he wouldn't be adding a feat that makes a characters attacks innately magical for purposes of bypassing DR. Does that really mean there are no ways to bypass DR?
Awesome damage is a fairly reliable method, and from what we've heard I'll bet we will at the very least see characters capable of awesome damage. For instance, if a feat or class feature offers a called shot ability that allows them to spend an action point to threaten a critical, that's a good way of getting through 5 or 10 points of DR. There might be a called shot mechanic that provides a means to impede or neutralize flight. And there might be a "second wind" ruleset that provides an emergency reserve of hit points when it's most needed. All speculation, of course. Just thinking up a few magic non-intensive ways to prevent the IL party's defeat at the dragons hands as a matter of fait accompli.
Whatever fixes Iron Lore may have in store for player characters, I can't imagine that every PC should expect to be able to knock a dragon out of the sky with his bow.
True. Perhaps it takes the right party makeup, just as it would with a vanilla D&D party, who themselves may well be short on such resources as flight or magic arrows at the time of the encounter (imagine the PO'ed barbarian waving his +3 greataxe in impotent rage). Perhaps it takes an Arcanist and at least one Archer. Encountering a dragon on open ground is certainly a troublesome proposition even with access to magic.
If the "fix" is a story fix-- that is, the GM creates a cave nearby for the PCs to retreat, or they get some friendly magical assistance to help them fly, or defeat the dragon's DR, or its breath weapon, or what have you, then that doesn't really address the system issues of playing any monster directly out of any d20 book.
I don't know what Mearls is getting at, but it is certainly in keeping with the conventions of the fantasy genre to face a foe that simply can't be beaten without figuring out its weakness, which may require taking certain steps within the context of the plot. Kolchak the Night-Stalker faced guys like that on a weekly basis (for about 13 weeks).
For instance, werewolves as they are traditionally portrayed in fiction aren't supposed to be just a little tougher to fight without silver weapons, they're supposed to be outright unkillable. However, if the players don't think to smelt the silver coins they found into crude blades, does that make the werewolves worthy of a higher CR? Should any given monster with DR receive an arbitrary boost to its CR wheneve none of the characters happen to have the right type of weapon on-hand?