What can I expect when pursuing a degree in computer science?

Previous answers focus on the programming aspect and expectations of technology, but there's more than that to a CS degree. There's a lot in the theoretical part, algorithms, computability, mathematics etc'. What you should expect is a lot of hard work, it's a very demanding degree, but with that a lot of satisfaction from the parts you like. You can expect to write code and "be a programmer" but far from that alone, you should expect to tackle deep mathematical ideas and complex theoretical notations. Like with anything, there will be boring courses as well as interesting ones, easy ones and hard ones etc'. As for expectation for life with such a degree on your belt, a job in the high-tech industry is probably most popular and most often as programmers (at least to begin with), but that is not all there is to it. There are fields of research in the academic world and practical involvement in almost any field out there for computer science (biology, physics etc', even archaeology).

What you'll get are the basic, fundamental, important ideas in computing that you'll be able to use for a lifetime. What you won't get are whatever languages and frameworks are hot at the time, except in occasional specialty coursese.  Even there, you'll get a lot of stuff that will be forgotten in a few years.  For example, I took courses in APL and Snobol.  You probably haven't heard of these. What you probably won't get, unless you do an internship or are very lucky, is exposure to the real-world problems that exist in producing actual code realistically, as opposed to toy codes for class. I am mentoring an intern now.  He has never written a code longer than 1000 lines, except for participation in a class project of which he only wrote a small portion.

Here's what you can realistically expect. If you have no programming experience, you may find your introduction courses challenging and mind-bending at first. The most important advice is to not give up even if you don't quite "get it" at first. Your professors for your introductory courses have a huge impact on your fundamental understanding of CS. If you are stuck with a bad professor, seek out the assistance of someone else whether that's a different professor, or an upperclassmen CS major. You will make errors. All the time. Learning how to correct those errors is where the real learning happens. You will spend many hours on your own coding. Do NOT let it overtake your social life. Even if you are not the most outgoing person, college is the best opportunity to meet others and network with them. This is incredibly important when you are searching for an internship/job when you graduate. Most people do not know the difference between a Computer Science major and an IT major. You will probably get a ton of questions about people's problems with their computers/phones. Getting an internship is the best thing you can for do for your future career while in college. Get exposed to as many languages as possible, whether that means on your free time or in a class. Taking your own initiative to learn something is a great way to get ahead in the CS game.