mmm wow, that is certainly a handful of things it must be able to do. I really think you are going to be pushing any software to the limit and I doubt very much you will find a single tool that will meet your need. I do not believe in the "one-size-fits-all" approach, diversity and creating optional outcomes is a far more successful strategy in the changing IT environment than a single option tool.
Please do not forget that most PHP apps are not yet that HTML5 friendly... and I am not sure how far Moodle 2.0 is from that.
Moodle 2.0 will certainly meet most of those requirements, and some LMS' will not meet any but the most basic. Graphics for any LMS is always going to be an issue, but more so with the PHP Apps handling of different graphics types. I doubt that any PHP based LMS is going to be able to handle a lot of visual presentation tools all that well, ditto for any programmatic tools either. It is more likely that you will find an LMS that can handle a few media file types well, but not that many really. The Moodle/Mahara, or mahoodle integration is a blend of two tools that allow a new adaptation of some of the basic ideas you want to explore. No single proprietal tool will do what you want, despite the promises made.
It is your FaceBook/Social Integration points ideas that would fascinate me I can tell you. How do you envisage this working? No doubt you can access them via Moodle or maybe vice versa, however you set it up - but why would you want to? Every Monday morning there is always some drama about FaceBook with our younger students.
Moodle is free to download, free to operate, not free to use though, you still have to buy equipment, server space and so on, still need a techie to operate the hardware, and maybe if you want a professions Moodler to administer it, or more likely, a part timer who is willing to take it on, unless you are hosting it somewhere, which is also going to cost.
A good bet: download a copy of Moodle 2.0, set it up and use it. Try it, break it as often as you can, and find out how to fix it. Do as much as you can to prove what it cannot do - then see if anyone else has a product that can do better. That will answer your questions better than anything else.
Better option: Use a number of tools that can be blended, not necessarily integrated. A Moodle/Mahara/MediWiki/WordPress blend should meet just about all your needs, and without costing a lot to setup and own I believe. Each tool does different things very well, and that should take care of most, if not all, your needs.
The beauty of these tools, you can download and set them up to suit yourself, you have control of them, not someone else, not some nameless or faceless disembodied voice or emailer on the other end of the line. They are all open source so you may want to set up a full integration, to suit yourself, and you can do that, you don't have to wait for some executive in some bland corporate office halfway around the world to agree with you.