1) The itemization system: Rare items are not rare and 99% of them that drop are junk(it seems that most weapons could use a bump in base damage with a reduced range of damage modifiers with an end result of higher DPS on average per weapon found). 75% of legendary items are designed so poorly that they are not useful even with the best rolls. The other 25% of legendary and set items that can be useful, are victims of a poorly designed affix/RNG system. You're lucky if 10% of them roll well enough for someone to want to use them.
A limited number of affixes are desireable. When the other affixes appear on an item, they take away the chance of a useful affix. Major buffs to the "not so popular" affixes could make them viable.
A character's DPS output is almost completely dependant on items. Instead, they could have a better blend of being able to increase skill powers while leveling and supplementing those skills with items.
Not all character skills can be improved via affixes that appear on weapons and this is leaving players with certain skill sets SOL for improving them via item affixes.
They need an item sink which could be as simple as combining 4 rares, 3 legendary or 2 set items for a new item roll.
They should consider allowing higher level gems drop in inferno. At this time, item drops are so boring and the odds of having something useful drop are extremely low. Adding higher level gem drops would spice things up a bit.
I would also suggest one last thing to improve the item hunt. Add a new rarity(75% less frequent than Legandry drops). It could have red lettering and beam or light or such. Something that, when it drops, is almost certainly an upgrade. They should be designed specifically for classes (like some set items). They would not confer a set bonus, but several class specific skill upgrades. They would not roll random attributes, they would automatically come with what your class uses, such as an automatic 300 Int and 200 Vit for a Wizard. If it's a weapon, it has a socket! When they drop, you are truly excited. You aren't thinking "well it's a set item, but if it doesn't roll well, it's worthless". You know right off the bat that it's awesome.
2) VERY limited character progression choices: As we level, the game chooses a skill or a rune that opens up for us. We can choose to use that skill/rune or not. Every once in a while we can choose one of three passive abilities. We can choose gear for our character. And that's it! How about adding a trait at character creation? How about choosing character appearance at creation? How about gaining some bonus that we can choose from at each 10th level milestone? How about letting us choose whether or not we want to assign ability points? How about letting us choose a "Feat of Power" from a list of choices every 20 levels(it would receive a skill slot on the skill bar and have a long refresh timer, but be powerful)? Basically, what it comes down to is allowing us to make choices that make our character different from other players characters.
3) Limited Content: Let's face it...the game is very boring. They need to add charms, jewels, new "old" gems and runes (they also need to create some new item slots and ideas for items, this shouldn't be exactly like D2). They need to make crafting useful(both Jewelcrafter and Blacksmith). They need to add random map shapes. They need to allow some monsters types from different acts to sometimes appear in other acts. They need to add rare mini boss spawns to zones(similar to Key Warden, but a random spawn). They need more random dungeons that can appear. An endless dungeon would be a great addition, but I would suggest many different designs, otherwise players will get bored of this right away too. And on and on...
I like the game, and it's going in the right direction. There is a lot they can do, so I'm still hopeful. I especially like the beam of light they added to legendary and set items(although I do wish set items had a green beam of light). Reduced ID times was a great start, but should be removed. They are doing great things. I can't wait to see what an expansion brings. If it's just a zone and a new class I'm going to beat someone though.
Edited by Tuftronic#1760 on 11/30/2012 9:43 AM PST