At least he's been cited: Google Scholar reports 1600+ citations for The Singularity is Near as well as for The Age of Spiritual Machines, his earlier book on the same theme.

Also, if we're talking about him in general, and not just his Singularity-related writings, Wikipedia reports that:

Kurzweil received the 1999 National Medal of Technology and Innovation, America's highest honor in technology, from President Clinton in a White House ceremony. He was the recipient of the $500,000 Lemelson-MIT Prize for 2001,[6] the world's largest for innovation. And in 2002 he was inducted into the National Inventors Hall of Fame, established by the U.S. Patent Office. He has received nineteen honorary doctorates, and honors from three U.S. presidents. Kurzweil has been described as a "restless genius"[7] by The Wall Street Journal and "the ultimate thinking machine"[8] by Forbes. PBS included Kurzweil as one of 16 "revolutionaries who made America"[9] along with other inventors of the past two centuries. Inc. magazine ranked him #8 among the "most fascinating" entrepreneurs in the United States and called him "Edison's rightful heir".[10]