Here are my suggestions for patch 1.2. A focussed set of low effort/high benefit changes.
Crashes under Vista. These have to be the priority sadly.
Ridiculous loading times. Some people are waiting several minutes... this will affect their enjoyment more than anything else...
Clear up the inventory. If I find myself thinking 'Hmm, think I brewed a potion to let me see in the dark a couple of nights ago', finding it among the grid of similar bits of coloured junk is ridiculously hard. Give items of the same type a coloured background or something, auto-sort, or separate the ingedients (which you tend not to need from the inventory screen) from everything else. Easy win. And if I do have to mouse over things and wait for a tooltip to see what they are... don't cover up the other items with the tooltip. Quite probably you've just hidden the thing I was looking for...
Don't turn off quickload when I'm dead. This is silly
As part of the same problem, the number of saves that build up (my save folder is 3GB) mean the load screen takes ages to come up. Just put the quicksaves in 3 quickslots - don't give me yet another large file every time I quicksave.
Stop putting that sword away dammit! Geralt sheathes his sword after a while, regardless of the danger he's in (and I think, on searching). This is not helpful. The related problem is that when this animation is running, Geralt ignores move commands, so you can be holding W, trying to get him out of trouble and he'll ignore you until you press W when the animation has finished. Or if you're running and he decides to sheath the weapon, A & D don't work until he's finished. And if you hit W while he's unsheathing manually... it's ignored.
Stop kicking me out of dialogues. Some dialogue options end the conversation, and others don't, with no obvious pattern. Once I'm kicked out I have to wait for the NPC-sitting-back-down-animation to finish, click on them again, wait for the 'cutscene' effect to fade in, listen to the same silly out-of-context 'Geralt, fancy seeing you here' line and finally get back to the other thing I wanted to say. This is just daft.
Stop repeating the 'Hey, Geralt', 'Witcher?'. 'Ow Geralt I've hurt my toe' intro to each character's dialogue tree. After the first time, these tend not to fit the situation, slow things down, and sit badly with the problem above. We don't need to hear them every time we talk to that NPC, we certainly don't need to hear them before every line that NPC has. This does happen sometimes.There are countless other tweaks and enhancements I can think of, but these are the ones I think would clear up the most frustration for the least effort. For 1.3, we can talk again
Anyone want to add anything that's simple to understand but would have a wide-ranging effect?