I still disagree about Ning. I still think the marketing copy on their website comparing Ning to flickr et al is disingenuous and I still think that Ning won't fly in the long run. However I still believe that in the long run Diego will be even more successful than he is now because he's a smart person who gets things done.
Good questions. :) Just a few points:
1- We're not comparing the photosharing app with Flickr. Flickr is an awesome service, but it serves a different, albeit related, need. The Flickr comparison is just to frame what it is, not to say that they're the same.
2- "they get my app" -- everyone developing apps on Ning benefits from what others have done. That's why the license for the code in the playground is Creative Commons.
- If you have enough knowledge to set up your own service, you probably won't have a use for Ning, and that's cool. Consider though: many people have enough knowledge to tinker but not enough knowledge (or time) to maintain a hosted account, or manage a DB, and many people could benefit from being able to use these app patterns for their own needs, without having to go through setup and maintenance.-
PHP: over time we'll be adding support for other languages, such as Python and Ruby.
- URL ampersands and such: I hear ya. We're on it :)