NicoNicoDouga's uploading ruleset:
It'll cost you 540 yen a month to get access to this -
The video upload file size for recommended video formats (*1) is raised to 100MB(40MB for free members).
Resolution / Bitrate
No resolution limit (Free Members are limited to 1280x720), no limit in bitrate (Free Members are limited to 600Kbps).
Video Upload Storage
Premium Members receive 8GB of upload space and +1GB for every month they continue their Premium Membership (*2)(Free Members are limited to 2GB no extra)
Get priority when uploading during peak traffic hours (7pm to 2am).
For a bit of perspective, at a 100MB/video assuming 2 minutes and 15 seconds, you're looking at an effective bitrate cap of about 8mbit for the video and audio.
For even more perspective, youtube runs at about 4.5mbit on their 720p videos, last I checked.
Edit - cause I can't do math at 3am when I first replied Megabit != Megabyte - This is acceptable as far as I'm concerned, but not great, as long as all videos remain short, but you'll have to remember to reencode everything exactly to their specs, so you can't get lazy. The rest of the critique remains.
For a note - I encode at 30mbit, so my standards are much higher, and nico will only do downconversion (for the purposes of their free/subscribed difference). You definitely don't want to run beyond about 10 minutes, because that WILL take you into streaming territory (Sub 1mbit).
Also note that you are effectively capped at 10 videos per month, due to the fact that a premium account will only 'grow' by 1GB per month.
Of course you could make videos smaller, but that will hurt the quality further.
Then of course there's the peak time restrictions on your viewers and the quality degrading (Can't view the original source video so no matter what you do unless you subscribe, most people will see an even more significant quality drop), but that will be up to the user to pay for.
The advantage (?) is that they are headquartered in Japan, so consequently, NBGI would be subject to the same risks as the main community (And are consequently less likely to nail you with a notice, since it gets messy really really quick.)
In balance? I don't think Nico is good for more than a stopgap, mostly due to the video cap, unless some people can live with 10 videos a month.
As well, Maka, could you PM me the contents of those notices? I need to check something.
Edit: My calculations were off when I first attended to this at 3am.