I understand your point. I didn't know Dropbox supported that large of files. I use it for work purposes to sync my iPad, iPhone and desktop.
Another point. Dropbox may not support the bandwidth necessary to stream a video, particularly if it's HD. I'd have to research that further, but something tells me it either won't be enough bandwidth, or if it did work you may receive a not so nice email about your usage. Better research that before going too much further!

I just did a quick search. I don't think Dropbox will do what you want. Here's from their FAQs:
Please note that when you create a link to a video in your Dropbox you will be able to watch the full video, and anyone you share the link with will be able to view the first fifteen minutes on a preview page. In order to view the full length of the shared video, recipients will need to download the file to their computer.
So unless you are logged into your Dropbox (which Serviio can't do for an online source to my knowledge) you can only stream 15 minutes. If your files are that large, I don't think they are that short.
