I read Michael's Blog and that he wants a better blog alert system. I agree to him that we cannot (or there is not need for it) to subscribe to every blogs feed that we comment on. Below are my suggestions.
Well I agree, that there is a problem here, but here are my suggestions:-
1) As you said, blogs should have notify function in them, yes might be helpful, but think of negatives too, how many people would provide their right email address on the blogs? I know aboutmyself, I never do, although I would have my right blog link :)( I fear SPAM). Then think of the network bandwith it will utilise, there will be tremendous amount of email jumping all over the internet. After a while, I am sure you will yourself be tired of this option, as you start visiting 1000 blogs a day and respond to 300-400 of the posts in it. I don't think that you want to get notified for 300Post X 5 replies each post times in your email!
2) I know now most of the smart bloggers use services like Technorati & Feedster to track their blogs, so if you think that you have anything susbstantial to add to the post on a blog, link to that post on your blog and comment on your blog, as I am doing it now, this will have two benefits, the moment you comment on it, it will be tracked by the other blog and a link would be created there showing that you have replied and also you will have more people visiting your blog. Check your referrers from time to time and follow the links.
Periodically search services like Feedster.
3) Maintain a list of blogs that you comment on and use web content management tools like Onfolio, Contentsaver or Keepoint (with Keepoint you can configure when you want the content to expire,which is a neat feature) and put them in a folder and check the links periodically (should not be very hard to do this).
4) Use Google Alerts services, lately for me they are proving very useful.
5) Subscribe to the feeds on temporary basis if you think that those responses are really important and may be create temporary folder for such feeds and aggregate them in that folder, mark the threads that you want to monitor (flag them)
6) Periodically search in Google, for example because my name is not so common, I search on Google with this string and I get most of the places where I have commented, you can be a bit creative in this.
7) Can you think of any more...
8) Can you think of any more ....
Tejas Patel