Iosue
Legend
Since he expounded on the Basic, Standard, Advanced categories, Mearls has always used "core" to refer to the Basic game. The Basic game will be made up of systems used by all tables, though the form of those systems may differ from table to table. E.g., non-magical healing will be in all games, be that the low-recharge rate of the Basic game or a higher recharge rates or Hit Dice for tables that want that. Skills (and Backgrounds) were initially optional, but were made non-optional in the Jan. 2013 packet with the expansion of the skill die to the Basic game. The idea being that even if specific skills were not used, players of the basic game could use the skill die on ability checks at DM's discretion.I guess that was a failure of communication on my part.
From the very first packet, we've been told that skills were optional, but were going to be included in the core rules. Lately, they've backtracked on that, and have made it sound like they won't be. That is why I am concerned.
[Edit] Here is the article I'm talking about http://www.wizards.com/dnd/Article.aspx?x=dnd/4ll/20130422
The new direction Mearls outlines in the above article is to again remove skills from core (Basic rules) in favor of an optional model (Standard rules) that uses improving static bonuses.