I don't see how after that video and that post how he wouldn't be accepted unless the YC people have some pre-existing opinions about the future of online storage.
1) i have other people working with me on this. i did prototype it alone, but i don't intend to be a single founder. i won't belabor it here, but it's really a good idea to get other people on board and the reasons yc and everyone have for not encouraging single founders are valid. your odds are much worse, and playing superman gets old after a while when you're trying to do everything -- and it's more fun to have more people involved and excited about the idea anyway.
2) re: applying: i am applying for this round, but actually didn't apply for funding for the last wfp. however, i did apply 2 years ago (with a cofounder) with another idea and wasn't selected.