Reddit reviews The Art of Scalability: Scalable Web Architecture, Processes, and Organizations for the Modern Enterprise

Some more:

The Art of Scalability - Well, the first 2/3 of it.

Scalability Rules - Very good, very short.

Continuous Delivery (I'd argue this is the single most important book in the software industry in the last 10 years)

The Little Redis Book - Free download!

The Little MongoDB Book - Free download!

The Varnish Book - Available as a free PDF if you fill out a marketing form.

10000 limit again. Reserving this comment for the Programming section:

PROGRAMMING
Gray Hat Python: Python Programming for Hackers and Reverse Engineers
Beginning Python
The Python Standard Library by Example (Developer's Library)
Shell Scripting
Shell Scripting Recipes: A Problem-Solution Approach
Linux Command Line and Shell Scripting Bible, Second Edition
Wicked Cool Shell Scripts
sed & awk (2nd Edition)
The Ruby Programming Language
Beginning Ruby: From Novice to Professional
Ruby on Rails 3 Tutorial: Learn Rails by Example
Agile Web Development with Rails
Automating Microsoft Windows Server 2008 R2 with Windows PowerShell 2.0
Pragmatic Guide to Subversion
Programming Perl
C++ Primer Plus
The AWK Programming Language thanks sjhill
Modern Perl thanks three18ti
High-Order Perl thanks three18ti
The Art of Scalability thanks mr_chip
Scalability Rules thanks mr_chip
Continuous Delivery thanks mr_chip
The Varnish Book thanks mr_chip

The ones I see most often are The Art of Scalability, Building Scalable Websites, and Scalable Internet Architectures, although I can't say anything personally about them. There's a question on SO that would be useful if it wasn't closed. And there's often good stuff on the High Scalability blog.

I'm not aware of any recent books, though, no. I've started a book about that and some other stuff, but along with not being finished it's probably targeting lower traffic than you're looking for.

I'm looking at this and this book at the moment.