Things I'd Like To See:
1) Tracking: It's More Than Just "Duh, Dey Went Dattaway!" See the last edition of the
ENWorld Players' Journal for my solution. Identifying creatures by their tracks, scat, telling things about them, etc.
2) Race and Age mean something. See a later edition of the
ENWorld Gamer for my solution to that. Each Race gets certain racial background points, and skills to spend them on.
3) No blank levels. Every class gets a new ability, feat, or something at every level. They shouldn't all affect combat, but each class should get a goodie at every level.
4) Fighters get paths, which give them predetermined abilities at each level where they don't get Fighter Feats. Cavalry starts off with Mounted Combat, Command starts off with bonus to CHA, eventually leading to Leadership, while Cavalry gets horsemanship feats. Marines get shipboard fighting feats, etc.
5) Every class gets +1 Skill Point/Class Level in ALL Class Skills, PLUS their current Skill Points... These may be spent to maximize skills, or for Cross-Class Skills, as desired. Maximums are done as now.
6) Use Rope is done away with as a skill, entirely. Tying knots is done with either Survival or Climb, whichever has the higher bonus. Throwing a grapnel is done with BAB.
7) Forgery is rolled into either Bluff, or Sleight of Hand.
8) Fighters are allowed access to Profession, as well as Knowledge (History & Architecture and Engineering). This will aid those who multi-class to Bard, yes, but is intended to reflect their knowledge of battles and fortifications. Again, this could be related to their path... Marines getting Knowledge (Architecture and Engineering) later than Militia or Guardsmen. At later levels, other skills can be added as Non-Cross-Class Skills, such as allowing Army path Fighters to acquire some survival and Knowledge (Geography), or even add them as class skills (+1 Skill Point/Level) from that point on.
9) Roll Sorceror/Wizard into one class, give the Sorceror the bonus magic Feats, and make them two variants of one class.
10) Do the same with the other (Semi-)Spellcasters. Make a Spontaneous Casting variant of each, and a Studied Caster (with Scribe Scroll as a free Feat) of each. The player chooses which one they want their PC to be.
11) In relation to 3, lots of new special abilities relating to the "Job" of each class, and similar Class-only Feats... For instance, the Druid might get
Speak With Animals as an At-Will Ability at a certain level, and a Ranger or Bard might have a Class-only Feat to allow the same ability.
12) Spellcraft is done away with as a separate skill, and all Spellcraft tasks are performed with Knowledge (Arcana).
13) Bards automatically receive Perform (Voice), which includes all aspects of singing, oratory, poetry, whatever, as a freebie. They may then spend their skill points/level to maximize this, and/or on instruments. This solves the "No one will ever take an instrument!" problem.
14) Concentration could be removed as a skill, being rolled into Knowledge (Arcana), as well (although the Class Skills lists would have to be updated).
15) To reduce the reliance upon magic items, "Items" should be buyable as a "Power", instead. So you buy "+1 Power" instead of a "+1 Sword", and any weapon you use is treated as +1. Same with armor, etc. Then other special weapons/armor abilities can be stacked on. This needs playtesting to see how abusive it is, but sounds good to me.
16) I'd like to see more weak, permanent abilities, instead of "X times per day" ones. It's an aesthetic thing...
17) It'll Never Happen: Spells all have a spell failure chance... You start with 50%, and go down from there (just like a Fighter's chance to hit). Spell damage is greatly reduced (in line with weapons damage), but can also be used at will, as long as you have components. Eventually, you get to 100%, but new spells start at 50%. Thus, it is better to use a "Sure-fire" low-level spell than the handy-dandy new Zappathingum you just got.
18) PCs start getting the powers, abilities, and skills they need to do their jobs, and have something left over to flavor themselves as they please.
19) Characters stop being incompetent at low level. They can do things like throw a punch without needing a Feat to do it (right)! Maybe a Mage needs Improved Unarned Strike to do this, but every fighting man (Fighter, Paladin, Ranger, Barbarian, Rogue, even Druid, maybe even Cleric) should be able to, without the -4 penalty and AoO! Same with Disarm, Grapple, etc.
20) PCs should be more knowledgable... The +1 to each Class Skill/Level will go a long way towards fixing this, and the racial background skills will, too.
That's it, for now... I'm too hungry to go on. Suffice it to say that D&D would look much different, if I ran it. Tying a steenking knot would be pretty easy, and everyone would be more able than disabled!
21) Oh yeah... and Rangers still need Balance, so they won't fall outta da trees, and offa da cliffs! ;-o