http://highscalability.com/ - weekly newsletter about scalability, distributed computing, computer science, and other relevant things. I don't think it gets attention it deserves - it's really, really good and contains wealth of (mostly) timeless information.

Also, Reddit. Not the default front-page stuff, of course, but more in-depth and smaller subreddits, such as /r/netsec, /r/financialindependence, or /r/rust - there's a multitude of nice focused communities. Occassionally even /r/programming is more interesting than Hacker News though :)