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Update again:
Broke the 4-hour mark!
https://forums.factorio.com/forum/vie ... =20#p66038
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UPDATE:
I did a new run in 4:44:42 -->
https://forums.factorio.com/forum/vie ... 730#p64730
Video's are online now:
The run itself:
http://youtu.be/3BBr_xtI5do
Commentary video:
http://youtu.be/2fgTJskwDlM
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I am working on a speedrun and I just finished a tryout/template kind of run in a very promising 5:23:43. I'll upload a video of the playthrough to youtube soon, if the replay works (I'm still on version 0.11.8, it should work as long as I don't update right?)
I still made a lot of small mistakes and some big ones, especially the end is slow (didn't manage the research efficiently enough). under 5h is definitely possible, maybe even 4:30. We'll see, hopefully I'll get a couple more runs in before the new endgame content is added

Edit: lpw suggested I'd include a statement about settings and such:
Disclaimer: this is a run on peaceful difficulty, with high resource richness. The map is generated with the normal factorio map generator, no custom edits were made. I believe in the speedrun community these rules would fall under a "any%, no glitches" category (in which you can pick the most favourable settings the game itself provides, but not make custom edits or cheat, or use glitches like for example the famous Minecraft duplication glitch.
However, the way this (and likewise, all factorio runs I've seen so far) differs from a traditional gaming speedrun style, is use the in-game timer as a benchmark instead of real-time (The game timer, for instance, doesn't include the time spent in the tech selection screen as the game timer is paused at those time). Also, I had to reload from an autosave at the very end due to an unexpected hilarious event (I'll show this in my commentary video). Likewise, I reloaded from saves two or 3 times when I screwed up big-time (I didn't do excessive reloading, as you'll see there's still quite a few errors in my run, including a big one which costed me 15 minutes or more! I'm thinking sub-4 hours should be possible with excessive reloading) I imagine most (or all) of the runs so far have a few reloads, anyway there is no way to check if this happened or not while watching a replay of a game, so unless you're running live in an official kind of way, one has to assume this happened. I guess that these kind of runs fall somewhere between a live run (where you play live on a real timer in one sitting) and a TAS run (Tool Assisted Speedrun, where you can use emulators, savestates, and basically program all controller input frame-by-frame to achieve the optimal results). I'm quite new to speedrunning, so if I gave a wrong description about any of the above, feel free to point it out.