purecharlie

I have run a successful members site for several years now and have always provided the videos in WMV format. We output the videos at a bit rate of 768Kbps so a 15 minute scene is only about 100Mb. This was originally done so no-one would have problems downloading the final scenes. However, as broadband speeds have improved over the years and as we actually shoot in much better quality than we export the final footage at, I am now looking to improve the quality of what we output.
Can anyone tell me if there are "preferred" settings for a video scene on a members site these days? For example, would a member expect a higher bit rate or are they looking to have the films shot in progressive rather than interlaced? Is there a maximum file size that we should avoid going above for, say, a 15 minute scene?
I have been discussing it with my video editor recently but I wanted to get the views of some of the guys on the forum here as well.
Your comments / views would be apreciated.
Thanks,
Charlie