Remathilis
Legend
Okay, now I see what you were saying re: the Marks. I still disagree; the 4e Eberron books were very clear about just how major an off-race mark would be. If I, as DM, didn't think it'd fit my campaign or I didn't think a player would be interested in dealing with the consequences, I'd say no, and IIRC the Player's Guide says to check with the DM first.
YMMV, of course.
(Edit: @Remathilis )
Here is my problem with that:
There was already no issue with a DM house-ruling the 3e version of that and just saying "X race can take Y mark." You're an aberrant and will be hunted, but mechanically its no different than taking any other feat. However, the default setting is that each race only manifests certain marks and the rules enforce that decision. Its up to the DM to decide if he will allow such oddities in his game.
In essence, the default setting is "No" unless the DM says "Yes".
By presenting it as an option within the rules and then giving the "check with your DM" cavaet, you're implying its ok and that its the DM deciding to stick to cannon that will disallow it. Some DMs I know would probably let it go (I wouldn't) and I know plenty of players willing to piss off House Orien just to be able to teleport 30 ft. The rules don't support the fluff, indeed the rules make excuses to get around it.
In that scenario, the default setting is "Yes" unless the DM says "No".
I tend to have a huge problem with "rare, special snowflakes" being a PC choice by default. How many Good-aligned drow have left the Underdark since 1988? Enough to fill a small city I'd wager. Nothing remains rare when presented as a PC choice. I'd much rather the marks be race-specific, and a sidebar mention to DM the ramifications of changing the rule than to have the rule be "Yes, but ask your DM just to make sure its okay." It just smacks of players having their cake and eating it too...