How practical is Automata Theory? There is always a way for application in topics related to theoretical computer science. But textbooks and undergraduate courses usually don't explain the reason that automata theory is an important topic and whether it still has applications in practice. Therefore undergraduate students might have trouble in understanding the importance of automata theory and might think it is not of any practical use anymore.

Is automata theory still useful in practice?

Should it be part of undergraduate CS curriculum?
Ever used a tool like grep/awk/sed? Regular expressions form the heart of these tools.
You'll be surprised how much coding you can avoid by principled use of regular expressions - in "practical projects", like an email server.
If you're a CS major, you'll definitely be writing a compiler/interpreter for a (at least a small) language. If you've ever tried this task before and got stuck, you'll appreciate how much a little theory (aka context free grammars) can help you. This theory has made a once impossible task into something that can be completed over a weekend. (And it won the inventor a Turing award - google BNF).
If you're a CS major, at some point, you need to sit back and think about the philosophical foundations of computing, and not just about how cool the next version of the Android API is. On a related note, it is the job of the university not to prepare you for the next 5 years of your life, but to prepare you for the next 50. The only thing they can do in this regard is to help you think - think of automata theory as one of those courses.