Gabbo?

Gabbo-like buzz for ArcGIS Explorer is building again (here for great picture). Does ESRI really need such an application to stay competitive, or is it more of a vanity project? I'll be an ArcGIS user again, but only on the desktop, and for selfish reasons I'd like to see the company not expend resources building a geospatial cathedral. On the other hand, an ArcGIS Explorer that is a viable alternative to Google Earth and WorldWind could help convince people that ESRI really gets the modern web platform.