Too bad they limited this list the way they did. I can think of a bunch more influential IT people whom I am sure most people have never heard of. Here is a list - google away:

Nathan Goodman - influential researcher who collaborated on the aspects of database transaction synchronization. His work largely contributed to the ability to serialize database transactions, thereby enabling the effective multi-transaction use of databases possible. Later became a founding member of MIT's Whitehead Institute for Biomedical Research.

Leslie Lamport - algorithmist extreme, his insights on coordination between computers within a connected distributed system paved the way for the development of concurrent and parallel programming.

Steve Warshall - Influential participant in the National Software Works, the BBN project that led to the development of the Internet.

John Backus - The IBM pioneer that led the development of FORTRAN.

Got to get back to work - more to follow.