Managed hosting for WordPress has really taken off since Page.ly (long-time meetup sponsor and host of our EastBayWP.com site) started in 2009. Managed hosting costs more than ordinary shared hosting, but provides extra service: better security, better performance, more expert support, daily (at least) backups, and WordPress and plugin upgrades.
Our aim for this meetup is to get representatives from all of the managed hosting companies to talk about their particular strengths, so we can better choose the right services for our clients. (For example, if you want access to phpMyAdmin, you should choose WP Engine, but Page.ly and ZippyKid are much easier for hopeless n00bs to get started on. WP Engine has the most and ZippyKid the fewest restrictions on allowable plugins.)
So far we have a commitment from WP Engine and are working on the rest.