Yes, it is true. According to Nica Times (www.nicatimes.org) tourism is up for this Central American country. "In the first five months of 2009, tourism in Nicaragua grew by 11 percent, even as most of the world experienced a downward trend". (See Nicatimes Friday 24-31 July 2009.
Could it be a more affordable destination? Could it become the next Costa Rica?
Here is some general information from the WTTC:
While 20 years old, here is a link for a open source book for your reading pleasure: