gps tracklog: Alternatives to Google Earth

here's been a flurry of discussion in the blogosphere in the last week about current and future alternatives to Google Earth. Here's a quick run down:
Microsoft - Speculation here surrounds the work already done for Flight Simulator X (see image at left). Frank Taylor (of Google Earth Blog) says about Microsoft Flight Simulator, "the views of the Earth can be amazingly realistic and, with some add-on satellite and aerial photography, MSFS can look more real than Google Earth's views."
ESRI - Scrappad posts info on the ESRI entrant, ArcGIS Explorer. More detailed information is provided by Glennon again at Geography 2.0: Virtual Globes.
NASA - That's right, NASA is in the game too, with World Wind. I have to admit, I haven't played with this one in a while.

What's driving all this? Certainly not an altruistic desire to create something cool for all us map junkies to play with. For Google, Microsoft and ESRI, it's all about commerce. You can bet that the first two are pushing hard and fast towards advertising and other location based services.

Here's my own wish list...contour maps and a better GPS interface, including strong waypoint, track and route management tools. If Google and MS won't do it (and it's probably not high on their priority list), maybe someone else will create a tool that interfaces with these mapping programs.

Related posts:
National Geographic to team up with ESRI
Windows Live Local
TerraServer to host local, state and federal imagery
Google Maps and Google Earth - Where are the topos?