There were many "mainfeeds" for blogs.gotdotnet.com and they didn't kill the non-MSBloggers. People will chose what bloggers they like, and subscribe to them. I don't subscribe to the main feed because that is just too much noise. I subscribe to the bloggers I like and the bloggers who don't post every five minutes to see who can make it to the top of the list. If you think the MS blogger feed is going to kill your hits, try blogging somewhere else and compare. I am guessing the 50gb of traffic a month isn't all going to a few MS bloggers, but others like yourself. Anyway, it isn't about the amount of audience, but the quality you bring to your audience.
"Now I'll have to work harder to get the readability that I'm 'used to'."
Nah, you get assloads of traffic from being on .NET Weblogs. I blog on starting a Richmond (VA, USA) .NET user group, and get no responses. Someone else blogs it here, and get 50 responses in 2 days.
You've got it good here. The people that *really* have to worry about content are the ones are on their own domain that don't crosspost to an aggregation.