  In light of recent evidence suggesting a nonzero present-day cosmological
constant, Adams, Mbonye, & Laughlin (1999) have considered the evolution of
black holes in the presence of vacuum energy. Using the assumption that Lambda
remains constant with time, and a conjecture based on a paper by Mallett
(1986), they reach the remarkable conclusion that black holes with current mass
greater than about 2*10^(-9) Msun will not Hawking evaporate in the distant
future, but will instead absorb vacuum energy and grow to roughly the de Sitter
horizon size. In this letter we reexamine black hole evaporation in the
presence of vacuum energy, and find instead that all known black holes will
eventually evaporate.
