Now I'll be the first one to admit that I'm running a lot of mods, but up until lately it hasn't been a problem.

Before, Skyrim would maybe crash once in a blue moon, it was fairly stable and did not trouble me much.

After 1.7, or maybe Dawnguard, or maybe Hearthfire, I've been getting random lockups (game just stops, music keeps playing but the game is frozen). I've got these on crafting screens and once just casting a spell. It's not thermal - my machine responds fine otherwise, I can alt-tab out and kill the Skyrim process in Task Manager.

And then there are random bust-outs to desktop, out of the blue - I got several just walking around (but after a reload, walking through the same area is A-OK).

Now it could have something to do with a pile of mods I'm running, but I doubt it - I mostly have armor mods and texture and only a few that actually affect gameplay, and like I said, it hasn't been an issue until recently. So I'm inclined to blame the latest updates, wonder if anyone else observed something similar?

Uninstall any and all mods, verify the files, refresh the INI files, and start a new game. Play for a while and see if you have any issues. That's the proper way to check to see where the problem lies.

For what it's worth, personally, I have not noticed any new brittle behavior with Skyrim. Of course, with Dawnguard, I have noticed a few bugs, but no CTD yet. I do have a lot of hi-res mods installed, and some quests.

My opinion and experience is that with mods, the user always steps a little bit further out on the thin ice each time. As with deaths_souls recommendation, when things get really bad, it sometimes requires a fresh start, and then incrementally re-evaluate each mod before using.

Well what you need to understand is that the mods dont work for skyrim like they did in oblivion anymore. So if you install a mod for your game with scripts on it, then it's for keeps, in many cases even updating a mod can cause errors in your logs and serious problems. If you keep that in mind you won't run into any problems. I run a havily modified skyrim with 71 hours of gameplay and just by keeping that in mind i don't get a single ctd ever .

I swear I've seen this exact same statement regurgitated in other threads
Nobody seems to be digesting this information and explaining it (I'd tell you myself, but I have no idea other than it pays off to read uninstallation instructions for mods), just stating unhelpful information - and we can't start blaming everything on the fact that scripts keep running.

I posted a thread myself with similar issues. Arthmoor pointed out it could be due to Dawnguard because Beth botched a few things that can cause instability of the game. He said that in a few days TES5Edit will be out and we'll be able to clean it and hopefully fix the issue.

This seems to be the most likely cause, I'm just about to clean dawnguard and see if I get crashes
Will report back once I have