You can still do that of course, with the same file that you would offer your friends through your "web property". A file is still a file.
> Note, however, that your add-on may still be subject to further review, if it is you’ll receive notification of the outcome of the review later.
So other than hosting, I fail to see how this is different from distributing through the official channel — you still have to pass their review.
Note that I’ve never written a Firefox add-on (I’ve written plenty of Chrome extensions though), so please correct me if I’m wrong.