According to a July study done by BZ Research, 3 out of 4 development managers are or will be using Ajax in their projects.
This is a great indicator as to the growth of Ajax-based technologies and the maturity of the market. With frameworks like JQuery, Dojo, YUI & MochoKit becoming more feature rich, you can expect further acceptance of Ajax in the near future.
Read more here in the Software Development Times article: