Awe, crap, I don't have the PHB, so why am I posting this?
--- Well, since I am running a Pathfinder game on the Paizo site, I thought I try some ideas to get mileage out of your ECS or Eberron Player's Guide.
- Dragonmarks can be the result of a background or a trait. Feats are more important resources you can get when you get an Ability increase, and you don't have to take them.
- Racial abilities are handled differently in 4e or even 3.x. Use the human rules for Kalashtar, but add +2 to either Charisma or Intelligence. For Shifters, use human rules but take a look at the Pathfinder Player Companion: Blood of the Moon for ideas on how to handle Shifters. For Changelings, human rules as a base again, but add +2 to dexterity (I think). Base Warforged should get +2 to Strength or Con, but +1 to the other. Variant Warforged should be up to the DM's discretion.
- Artificers: take a strong look at the Alchemist in the Pathfinder APG. I'd say adopt the Alchemist from the Pathfinder APG with some changes, and make an Artificer theme for the Alchemist. BOOM BABY! (The Pathfinder Alchemist class is the better Artificer class, you just need to theme it to Technology and Item Creation).
This does require two extra books. Pathfinder Player's Companion: Blood of the Moon and Pathfinder's Advanced Player's Guide. But this is my loose and fast ideas for running Eberron in 5e using your 4e Player's Guide. When I actually get the 5e PHB, I can do a more detailed conversion. 
hmm intresting let us know how that is working out for the artificers. no artificer no eberron.
Papataz wrote:
Okay, I started on an Artificer conversion using the Alchemist as the base.
http://phaeselis.wikia.com/wiki/Artificer
I think I'd prefer the Eberron concept of the Artificer as a magical technician rather than the mechanical tinker style.
When I built a pathfinder Artificer I used the Alchemist class as well. Swapped Bombs for extra magic item charges, some of the discoveries for Magus, Wizard or Rogue capabilities relevant to magical items and other class abilities for item creation feats.
In 5th Ed terms, a Bard might be the closest. Shift emphasis to Intelligence instead of Charisma. Include benefits of Combat Inspiration with the base Inspiration ability, but require that it be applied to a specific item and the type of benefit chosen in advance. (So when you grant inspiration, you might choose to apply it to a weapon, for attack or damage, armour for AC, cloak for save, tools for skill roll etc.) Replace spell list with some buffs, and spells affecting objects rather than charms. Give Rogue Use Magic Device ability.
Ultimately though: I'd wait for the DMG to come out before trying to homebrew an artificer. Creation and use of magical items is pretty pivotal to the class and we'd probablt need the info in there to get a better idea of how to go about it.