The numbers are slightly misleading. 40% of those projects are gists (pastebin like service). While those gists COULD turn into full projects, it's doubtful. Thus the number is more like 600,000 hosted projects.
"Project" is a pretty ambiguous term, of course; there's gists that are multi-file full-fledged database adapters, there's gists with one-line bug fixes. Both could be more influential than full-fledged "normal" projects... it depends on the circumstances. I think each have their place in programmer society.
With the ease of forking even plain 'repository' is a relatively vague term.