It does add a new element of fear, the climbing spiders. However, there is a solution that no one here has yet mentioned, as well. There are two types of blocks, and only two, that spiders cannot climb. One is Sand, which isn't all that helpful as sand is nigh-useless to build with.
However, with the simultaneous inclusion of craftable Sandstone blocks, it is again possible to build outer walls that are impervious to spider invasion, if you prefer to keep your walls straight vertical. To craft Sandstone, just place four regular sand blocks in a square formation. Workbench not required, and it has the same resistance (30) as Cobblestone.
Also, a slight AI shift was made as well. Creepers previously had an ability to see the player through solid obstacles, which is how you were always turning around to find them right in your face all the time; they could see you through walls. This ability has since been removed from the Creepers and given to Spiders instead, in order to increase the probability of their making active use of their wall-climbing abilities now. This means that any spider nearby, whether you can see it or not, WILL make a beeline for your position, and will scale any un-spiderproofed obstacle to reach you.
Hide your kids.
Hide your wife.