I'm fairly new here, though I've been using Oblivion Nexus for quite some time now, and am an experienced modder of TW games, so not completely new! At any rate, here's some of my suggestions for improving the site:
1)
Allow comments to be posted with AJAX. Right now I'm typing this in a little window aside from my browser window using Firefox. I assume that's the default behavior. Most forum sites allow a 'Quick Reply' type function where a box appears above or below the 'thread view'. In fact I've switched to the forum mirror(I presume) of the thread since it was bugging me. In the case of Nexus I'd probably suggest such a quick reply box appearing above the list of comments, firstly because the posts are shown in what's known as 'Linear - Newest First' mode, so most users will be seeing the last comment up top and then responding, and secondly because it's more visible to new users unfamiliar with the in's and out's of forum or comment software.
2)
Allow switch to 'Linear - Oldest First' mode on comment view. This thread is showing as Linear - Oldest First, where the first post at the top of the first page is made by the thread creator. That seems to be the default behavior of most forums, and the backwards behavior of most comment areas. As someone who's more attuned to forums, I'm much more comfortable seeing the initial post first, and would therefore utilize the ability to switch it in preferences.
3)
Track downloaded files and receive updates. I've subscribed to the RSS Feeds for New Files and File Updates, and I'm also aware that you can sort it and view them on the site. When I view
this page however, it's a bit of a jumbled mess despite all attempts to clarify it with an image key. The truth is that when it comes to updates, end users are far more concerned with updates to the files, such as patches or new releases, than any other possible changes. What I'd propose is a way for users to say they've "Downloaded" the file, and subsequently view any new updates in a section of the member area. This area should ideally list only file updates they have not downloaded, similar to the way the site tracks downloads for rating files, so it shouldn't be that difficult to port.
Optionally there could also be a way to receive e-mail notifications when files you've marked as 'Downloaded' have received new updates(this works really well for places like CNet, Sourceforge, and so on). What this also can also do is allow a user to un-check "Downloaded" or just un-check notices for 'Downloaded' files, and then the "Downloaded" amount can be displayed on the file page. vBulletin.org uses this system, except it calls it 'Installed', and it's a more effective way to track how many people are actually using the file than the total number of downloads ever, or the endorsements. People will un-check 'Downloaded' when they've uninstalled the file due to issues, obsolescence, or other things, and that way the community will be able to convey to new users that while a file might be downloaded 80,000 times, it's possible it has been superseded and as such isn't marked as 'Downloaded' by many anymore. Naturally this last utilization is aided by the ability to sort files by most marks as 'Downloaded'.
4)
Allow modders a way to control file version intuitively. Popular project hosting sites like Sourceforge have the right idea when they have the Downloads trunk complete with all versions of the file, from newest to oldest with point releases categorized in conjunction with major releases. Not every mod will need a way to control versions, but the more long lived ones, such as MMM from Oblivion, could do with a way for users to see the file history, update history, and so on. This lets mod creators communicate when a release is a major release (v 1), patch(1.1), or quick fix(1.1.1). That helps users decide if they should update where it may break compatibility, and is more intuitive than the text-based changelog(but can still incorporate a changelog). This is not to say that all files should always be kept available for download on the server, but files could be marked by a mod creator as 'not legacy' so an older version persists if the newer versions take a different direction, and those be allowed to be downloaded still.
Furthermore, a couple other things could be included in the more elaborate downloads page for the benefit of end users. The first is a "Download Most Recent", or what have you, right at the top or even outside the 'Files' section itself and up there by the project name. Clicking this button would automatically download whatever is the latest full, point, or fix release(the mod creator should be able to change it, since some patches and fixes would be provided without the point release included, making them useless as a 'Latest' file). The second is a way on the improved 'Files' page to see what the latest version is that you've downloaded, presumably using the same tracking systems applied for file rating and the above suggestion concerning 'Downloaded' files. Maybe a green check to the left of the file name to signify which version you're on.
That's all I've got for now, thanks for your time and consideration.
EDIT: Oops, just realized I posted this on my old Nexus account, should really change the auto-login for the forums. :/