"So, if (or should I say when) runes as an item are removed, expect a very wide variety of +skill item modifiers."Just an interesting note about this subject. This was not announced in the recent Jay Wilson Rune Changes post, and most players are not even aware of it yet.
However, recent data mining of Patch 13 has revealed that +skills are indeed a new Affix for items.
Ancient Spear Increased by 3-5 (Barbarian only)These are not "skill points" in the classical sense, like in Diablo 2.. but rather smaller (and stacking) modifiers to increase the skill's effect, whatever it might be. For example, increasing damage, duration of the skill, number of targets, total number of projectiles, length or range of the skill, healing effects, etc. So, the number will either be a percentage (damage) or a number (time).
Bash Increased by 4-5% (Barbarian only)
Seven-Sided Strike Increased by 3-5 (Monk only)
Sweeping Wind Increased by 4-5% (Monk only)
It's sort of their way to still have "itemized runes" that can be sold in the Real Money Auction House. Now, these are just items that come with a mandatory Affix, but consider ultra rare drops (like one-use-only item enchants or unrevealed gems, that can also be sold on the RMAH) that can apply +skill effects to any weapon or armor of your choice.
Even though the Mystic has been removed from the game, expect it to make a re-appearance later in the future. For example, they have enough professions for the retail, so they're cutting out content now to save it up for the next expansion pack rather than dreaming up a new profession. (Blizzard has done this before.) And, with the Mystic might also come low end +skill enchants for any item of your choosing, rather than "Diablo Vanilla" only having the fixed +skills on gear.
For any new Affix they create, it will further increase the vast pool of total items, and therefore increase the total number of successful RMAH sales. Creating more items (even though they're really just the same) will be one of Blizzard's priorities given the new direction of the RMAH. It won't be just limited to weapons or gear; consider aesthetics for yourself or only for your followers, cool glowing or color-changing dyes, companions/pets, many new recipes, and even new gems. If the RMAH is great success, expect new items to start coming through patch updates (even in minor ones) or maybe even a rush of some things I just mentioned that they were saving up for D3 X1.
(Note: None of this has been officially announced yet, and many users on the Battle.net forums don't believe that this is going to happen.)