To settle this once and for all (though i do expect debate)

If for example Blood in the Ice won't trigger and hasn't triggered for the vast majority of the game, can a patch 'soak' deep enough to fix this issue, or will only new saved games get the benefits? Or the the results vary (ahh the beloved compromise)?

Patches fix game conditions which are used to move quest stages forward. If the game conditions can be reset, then the patch will probably allow a quest to move forward. If the conditions are in the save, then it may not fix it.

So, there is no way to tell on anyone's save if the patch will fix a quest until you load that save on a patched game and see what happens.

I've been following the most mentioned bugged quests but not looking too far into the 'why' they didn't trigger as to avoid spoilers to things I haven't done yet. This one triggered fine for me this weekend, and I did said quest. What exactly isn't getting triggered?

Bethesda best hope so because after having 170hrs of play time that could now potentially be obsolete I won't be starting anew with a fresh character with my fingers crossed.

The bookcase fix in 1.3 is a classic example of the OP's question...

Prior to 1.3 activated bookcases were glitched and you couldn't use books in them...they fixed this when they released 1.3 where once you activated a new book case it would not glitch but in your save already activated bookcases in your save stayed glitched.

This will be true of many quest glitches because the cause of the glitch has occurred and been saved in your save file and any patch that they release will not fix this, the only method of fix you can do is revert to a save prior to activating the quest ot start a new game.

All they patch is the quest glitching in the first place so it will never glitch on you when you trigger it but if you have already ready triggered it your stuck.

If a quest is glitched due to some part of the AI like the Radiant AI being messed up then yes they can sort that out since it isd game code that is bust and not anything in your save file.

Developers never patch a game that examines a save file and alters its content, they only fix their code that causes the glitch in the first place.

I await the final patch before I start my Skyrim experience...

According to the proposed 1.4 patch changelog, it is supposed to fix "numerous issues with 'Blood on the Ice' not triggering properly". In my case, and probably the OP's as well, the quest never started....at all. I walked into Windhelm many times at about 2:00 am, and the murder scene at the cemetery, which apparently initiates this quest, never occurred. I'm done playing this sluggish lag fest on the PS3 so I won't be downloading the 1.04 patch (if it ever comes out) in order to see if it fixes this,. In addition, I certainly will not buy any DLC for SKyrim, or any future Bethesda products either.

Unfortunately a side effect of this debacle of a release is that in navigating which bugs to avoid, I've basically been spoiled on everything this game has to offer. Lovely. Thank you Bethesda for a wonderful experience.

The simple answer is, sometimes...it depends on the quest/save.

Your probably safer to wait until the patching is finished entirely. Given the history of patching if may or may not go so well, so you may or may not end up with a game you're satisfied with. Which may result in you restarting again, and again - until the patching is finished. No one can predict what Bethesda will actually repair at this present time when everything is said and done, (I hope it's near everything in the game as the entire thing needs work) and not just the popular bugs to appease the largest mob with torches and pitchforks.

I know it's tough to wait this long to play a game many have been waiting for, but hang in there. Game companies are like a democratic style of government. We have say, but they will ultimately do whatever they choose to do. Let's just hope they choose well. For their sakes and ours lol. Myself, I'm still not sure if they are waiting for us to give the OK on the game, or if "we" are waiting for them to give us the OK to play the game.