Be neutral with your color scheme-There is nothing more useless than painting a wall a bright, trendy color, because the day after you're done, something new will be out and you'll be stuck with lime green walls (I was in middle school, lime green was hot, okay). On the other hand, there's nothing more tacky than sticking with a color for decades, because you have it lying around and it's always worked in the past. The school I went to for my Undergrad had a color scheme that had lasted decades, the color was called coconut dream and it always made me think of the color of the inside of my mouth (light pink, that is). Neither of these things work. Just like with our technology, we need to think ahead when we choose our decor.
Which brings me to technology-one to one technology is coming, it has to, because that is how students learn. With lower price points (I can get a Kindle for $79 now!), ubiquitous internet services (at least in the United States), and increasing support (technical and administrative) we have an infrastructure that we can use technology effectively in, giving our students the tools to succeed in the world at large. Laptop carts instead of computer labs allow the flexible spaces I talked about earlier, with the integration of mobile technologies.
Clean up your act-there is no reason a library can't be a friendly, safe, inviting environment and still be highly functional. De-cluttering, cleaning, and redecorating can help students feel more welcome in the long run. I see this where I used to work, there were piles everywhere, it was like a maze of stuff (books, mostly), no one used it because no one knew where to look for what they needed. Simple redecoration is removing superfluous things (i.e., anything that dangles in front of you when you are walking through the library space), cleaning the space, labeling appropriately (sorry, this is a bone of contention for me just in general), and cleaning (dusting, weeding, vacuuming and organizing).
Overall, I think it's adorable when they're talking about designing new spaces, because most libraries are forced to work with what they have (and that's sub-par a lot of the time), but these are all ideas that can be implemented, with time and patience, in any library.