This is now my favorite OS for everything other than gaming!
It's sooooo smooth and compiz manager is amazing too, I'm sure I haven't really gotten to the nooks and cranny of linux at all but it is a really great experience so far.
Eventually the cube, and all of the animations will grow old and become annoying. It's kind of like black lights, when you are a teenager they are great, but as you get older you realize they aren't necessary to blaze. Also, I hate to tell you this, but Ubuntu isn't a great distro to learn anything on. Ubuntu is nice if you just want everything to work out of the box, but you end up losing a lot of knowledge about what's under the hood. For example you don't need to really edit any config files, resolve any manual dependencies, and there are gui tools for pretty much any system administration task that you need to do. You won't become a command line ninja that way, and because of that you will lose a lot of functionality.
I recommend using Ubuntu for a while to get an idea of how Linux works from the outside, then switching to Gentoo or Arch to learn about how it works on the inside. Another distro that you might want to learn is CentOS or Fedora, not because you will learn anything, but because most web servers you'll use will use them. There are a lot of Redhat specifics that you should learn about(Ex: SELinux, RPM, etc). If you have absolutely nothing to do over a summer, then LFS is a great choice and will teach you much more.
Once you spend time in the trenches, you will eventually grow tired of editing config files and compiling software, and will come back full circle to a Debian distribution. If you like eye candy, ubuntu is great, but I recommend trying CrunchBang or a similar minimalist distro. Less is more sometimes.
