VNC: Yes, I know about TightVNC. It’s faster than VNC but nowhere near as fast and usable as Terminal Services.
Other people peeked in their server logs and saw .NET CLR penetration at around 6 – 8%. Some very consumer oriented sites are seeing even less (2-3%).
RSS: after much interesting discussion, the conclusion is the best way to reduce this bandwidth is already a part of the HTTP spec, and needs to be implemented by the aggregators. Kudos to Dave Winer who implemented it this weekend in Radio Userland. Hopefully other aggregators will soon get with the program — specifically NetNewsWire and FeedReader who are the most popular and thus the biggest problem. Presumably their customers don’t want to waste bandwidth, either, so it’s in their best interests. (And I don’t want to have to hide the feed from bandwidth hogging user agents.) I shall now shut up about this topic because I know it’s excruciatingly boring to the rest of the world.
Update 10/22: NetNewsWire fixed it. Good work Brent!