The Flash-based Galactic Plane Explorer has been replaced by the new Google-maps-based Milky Way Explorer. A detailed description of the content, sources, and usage can be found here:
These maps are in galactic coordinates and focus on major Milky Way objects. They are not intended to compete with all-sky services like http://sky-map.org/ that show millions of objects. If you are looking for a web-based virtual telescope, then http://sky-map.org/ is definitely where you should start.
Over time I'll be adding to the available Milky Way Explorer data. There are already a dozen different views available. Two of my favourites are the views that overlay an IRAS colour image over a galactic plane radio height map to create a composite "mountains in the sky" infrared/radio terrain that reveals a huge number of objects invisible at visual frequencies.
In addition to changing the interface and adding larger views at more frequencies, I've done more data mining using the Avedisova catalog, SIMBAD and the ADS to assign appropriate names to the Avedisova markers that appear at the higher zoom levels. I still have a lot more data mining to do - the ultimate goal is to produce a much more complete list of significant Milky Way structures than could be produced from purely visual frequency catalogs like the Sharpless or RCW nebulae alone.