One intermediate position might be for WMF to distribute virtual machine
images which can easily be installed on any one of a number of different
hosting services. OpenStack/Glance appears to be one such system, although
ops probably knows better. The current efforts with puppet and vagrant are
pretty close to this goal, all that's missing is identifying some
appropriate hosting services and closing the documentation gap.
This would also allow our existing community of MediaWiki hosting services
to migrate to the new VM-and-image-based model.
--scott
ps. as far as a business model goes for a MW hosting company, it would be
interesting to pattern it after github -- no charge for "open" wikis
(mandatory CC licensing, perhaps with ads, perhaps with size restrictions,
perhaps some amount of central auth and vandal protection baked in), but
reasonable plans for "private" wikis (with flexible authentication
integration and https support so that you can integrate it into your
company's infrastructure).