MapQuest removed free access to their tile servers with one month of advance warning — and no, requiring an API key is not free access, especially not with an imposed usage limit.
Their actions break all my maps, and I don't have the (computing and file serving) resources or knowledge how to properly render map tiles myself. And even then I don't know where to get aerial and satellite photography tiles.
What irks me most is that all of the data the tiles are based on are free to use, in case of OSM collected by thousands of volunteers, or paid by the tax payer for the satellite images. But you can't use them directly, because it's raw data and everyone processing it wants to cash in on it sooner or later.
So in the end, we're stuck with Google Maps and Bing again, which I bet will be seeing some monetization sooner or later.
The DIY Internet? Dead. Gone. A thing of the past.
Have fun with your high resolution V.23 service.