The primary reason I switched to Dreamhost two years ago was its excellent support for MediaWiki installs, one-click MediaWiki installs, and lots of space for user hosted images (I administrate something like five wikis).
And I was really excited that the one-click installs have finally gotten an upgrade, as more of the code I want to use on my DH-hosted wikis is accessible to me (not having MultipleUpload work was a real downside to some of my members, and we're thrilled to have it function).
However, there are still a few extensions and a theme that we'd really really like to use that are not available -- most importantly Bootstrap -- due to the fact that DH's mediawiki is still considerably behind MW's development.
An upgrade to 1.22 would make me and a lot of people super happy. Manually upgrading has caused nothing but disasters and data loss every time I've tried, requiring reverting to backups that weren't always perfect; please please bring us 1.22 as a one-click!