- Subscriber Control: I want to have control over who subscribes to my feeds. In particular, I need to be able to divide my life into at least four categories:
- Technical Contacts. People who follow me because periodically I write about something someone might find potentially meaningful from a technical perspective.
- Personal Friends. People who I know personally and might be interested in zoos and what train I got home.
- Current Coworkers. The main crux here is that there are things that I might want to share with ex-coworkers and personal friends, but not the current ones I have to see every day.
- Family/Near-Family . These are people who might be interested in stuff going on in my life that I'm not ready to share with other categories.
- Publication Buckets: I need to be able to publish any particular item into a bucket, or a whole feed into that bucket.
- Single Republication: I need to be able to take a URL from anywhere (e.g. treat something from Google Reader the same way as something I type directly into a text box) and have it appear to consumers the same way no matter how they choose to subscribe. 
- Single Inbox: Sometimes I consume stuff on my phone, sometimes I consume stuff on my laptop, sometimes I consume stuff from Random Web Application. I want "I read this" to mean the same thing on everything.
- Selective Subscribes: I might want to read stuff by Zack Urlocker on MySQL and Sun, but really not care how many miles he ran that day . I should be able to do that, combined with publication buckets.
- API Access: Anything I do with your web app I need to be able to do from any arbitrary app, potentially outside your control.
- Silent Unsubscribes: I need to be able to unsubscribe to someone without them knowing that I've done it. (More on why this is important anon).
Footnotes: Note to readers: If I've ever camped out in your house, or you have offspring who refer to me as "Uncle Kirk", you're in here whether I share DNA segments with you or not.
: Seriously, my life isn't actually that interesting. Except that I play with Pumas and Sun Bears and Ocelots and you don't.
: Note that this may mean either compliance on the part of the republishing services (e.g. Google Reader), or it may mean that I have a queue of pending stuff that I have to process before it gets republished; I'm fine with both approaches working together.
: I can say this. M7 Alumni In Da Hizzy!
: Not it. I'm secure enough in my 5k1LLz that I can say that these days, you want me to stay as far the heck away from the browser in a day-to-day coding perspective as possible.