I've just recently started using MSE and it's a great site. What I think would be a very neat feature is to be able to build a customizable home page on MSE so that I can see the new posts for the tags of my choice. So if I log into MSE, I see a page with say all the new posts for 'set-theory' and/or 'real-analysis' and which are being dynamically updated real-time, instead of having to click on each tag to go to its respective page. A lot like how I can modify the Google Chrome Home page to show different news streams. The reason for this is that I don't prefer the email option nor the rss option to get my updates. Neither are good for me.