Janos Simon is part of a dying breed, a generalist in theoretical computer science. Janos goes to most STOC and FOCS conference and few specialized conferences like SODA and Complexity. In three decades of research, Janos has studied complexity, algorithms (distributed, parallel, randomized), VLSI and networks well as having interests in nearly every area of theory. It's impossible to arrange parallel sessions at FOCS in way that won't cause a conflict for Janos.
Back in the 70's a graduate student could keep up with the latest research in all of TCS and produce significant results in his or her career in many different areas. Today we seem to push out very specialized researchers focused not just on some subarea like algorithms or complexity but even in more specialized areas like streaming algorithms or PCPs.
Such specialization has its risks, for example getting so caught up in an area that you lose track of the motivation for studying the topic in the first place. Also we lose some sense of community when theorists in different areas lose interest in following each others work. But can a young Janos Simon survive today as a generalist or are we doomed to further specialization as students search for successful research agendas?