I’m still using WordPress personally, and I still recommend it professionally. I do great deal of new site prototyping in WordPress (even if the final site isn’t). Even with the flexibility of custom post types, a fairly robust plug-in architecture, and the option of the multi-user network – I long for the lean, mean WordPress of 2004.
Or at least a viable competitor for a simple weblog in 2011.
I agree with Brent Simmons that this hypothetical system needs to have a 5-minute or less setup time. I don’t believe it should be in PHP.
I think client-side Javascript – it’s even more prevalent than PHP
For a while now I’ve been tracking Aaron Quint’s work on using sammy.js & CouchDB to build out web applications. While it’s not as technically mature as I’d like (nor do I have a sandbox up) it’s very compelling. Especially with CouchDB’s baked in versioning, feeds, and replication.