No.

edit: Your printed technical book was essentially worthless the moment you bought it, given how fast most software evolves these days. But, I'm guessing you mean: 'will this make my book so outdated as to be worthless in terms of learning.'

The answer is still no. All of the major new features are, essentially, optional, with the exception of jQuery, but hopefully you were already using that anyway.

The Asset Pipeline, SCSS and CoffeeScript are major new features, but you'd likely need to read up on SCSS and CoffeeScript separately anyway. The Asset Pipeline can probably be understood with a couple good blog posts.

HTTP streaming: same thing. Also, it's—again—an optional feature.

I'll agree with aaronbrethorst here: your books are going to out-dated regardless; it's the major downside to software hardcopy these days, especially web-focussed stuff.

Saying that, Rails 3.0 to 3.1 isn't like 2.x to 3.0 (where your books WOULD have been useless). A lot of the changes are evolutionary, and there's nothing stopping you from learning on the latest 3.0.x branch with your book before tackling the (fairly straightforward) 3.0 to 3.1 upgrade process, once you've got your Rails knowledge bedded down.

My rule of thumb: only buy tech books that primarily contain good practices by experienced devs. Good practices tend to survive longer than APIs, and provide long-term value.

I can't speak for other books, but by design the Ruby on Rails 3 Tutorial book is robust against this kind of change. The trick is to use explicit gem version numbers for everything. (I learned this lesson the hard way by watching my first book, RailsSpace, quickly go out of date.) Moreover, the differences between Rails 3.1 and Rails 3.0 are relatively minor, especially when considering how applications are structured. The Rails 3.0 knowledge you learn is still 100% useful.

That being said, I'm currently working on a Rails 3.1 version of the book. Stay tuned to http://news.railstutorial.org/ to get an announcement when it's ready.