NASA World Wind road map
According to the site, v.1.3.4 is expected in April. The developers will skip v1.4, and v1.5 will be released in September/October 2006. The road map enumerates several of v.1.3.4 features, including: 1) the ability to refresh elements in a layer, 2) improved implementation of shapefiles, 3) elevation data will include ocean bathymetry, 4) Mars and Venus datasets will be available--users will be able to access ten different Mars datasets, and 5) Sloan Digital Sky Survey SkyServer imagery will be accessible.
Version 1.5 will be implemented in .NET and Java, with an API-centric core. As such, the developers plan for the software to be accessible within users' web browsers.
The blog Bull's rambles, by a NASA World Wind contributor and forum moderator, reports that NASA has "hired Tom Gaskins to spec out 1.5 and lead the java team, also SUN have said they will hire a developer to help. The C# version will continue to be lead by Chris [Maxwell] and most of the current OS devs seem likely to stick with him."
By the way, I did a quick download check on sourceforge.net. Over the past month, NASA World Wind was downloaded about 11,000 times per day; during 30 days in late February-early March, there were approximately 330,000 downloads (~30TB).