I'm sure it will make modding much more popular since it's more accessible to newcommers, hence a larger scene and more high quality mods. And you can still keep using the nexus for you killable children mods!
Yeah because Nexus is so inaccessible.
This has a much greater potential to completely ruin TES mod'ing than it has at enhancing it. Everything from introducing avenues for restricting available content, to limiting ability for 3rd party tools to support the community (OBMM, OBSE, OBGE, etc.), to increasing misuse/unwarranted distribution of mods leading to great mod'ers to stop releasing their mods or only releasing them privately, etc., etc., etc. The potential here for bringing TES mod'ing to its knees its pretty clear and real.
I don't expect anything good to come from this. At best it will introduce people who know little about mod'ing to it as they pile on every available mod Steam has, completely destroying their game, then not finding or not knowing how to find support and turning potential new mod community members off mod'ing altogether.
I'm constantly amazed at all the PC people (the platform of users who bashed the Mac for decades over the fact that it was a closed system that they couldn't hack/modify/control) who seem to be so in favor of giving up what little control they still have.
Heck, the recent patch demonstrated exactly the problem of this integrated/centralized/no-control system - knowing that patches frequently cause problems, any number of us clicked the "don't do auto-updates" option in Steam.... and it proceeded to ignore that and do it anyway. And broke the game. (I can only run Skyrim right now because I was able to find v1.1 files. With Steam in Offline mode so it can't destroy my install again. Which means that I can't use Steam for the parts that DO work well and that I like. Yep, this is the right direction.)
Compared to Fallout 3, which when a patch completely broke 90% of modding... people just reverted their installs, since the patch installers were freestanding and didn't need to be used at all. (I still have a folder with every FO3 patch. Just in case I ever need to do an install to a certain level.) Going from this system to Steam automagically patching things unless you jump through hoops, with no options to revert? Progress!?
All of this too, well said.