Having just rolled Moodle out across the university here, I thought it might be worth briefly telling the Moodle community this has happened, and giving a little background for the curious.
I'm not too clear on the decision making for this, apologies for people who like to know that sort of thing.
For the actual move... essentially we had staffing from around the start of June this year, although we didn't officially start until the end of that month. Since then, my team (2.5 FTEs, and an assortment of postgrads to assist) moved around 600 modules' content from WebCT 6 to either Moodle or a locally developed tool, as well as developing a support framework for Moodle to tie it into local data services and training staff on their usage. A further 200 modules or so were moved by academic school's support staff or academics themselves. On Monday of this week approximately 10,000 users descended on the two systems.
I'm hoping that's the world's fastest move to Moodle. Certainly, we wouldn't suggest doing it on that timescale, and we have another 600-ish modules (which are not taught until next calendar year) to transfer before WebCT is shut down.
Initial response seems to be mostly positive. People who liked WebCT are distressed at having to learn a new system, but that's not terribly unsurprising. However, people who made light to no use of WebCT seem to be warming rapidly to Moodle, and initial impressions are that usage is higher than WebCT.
We've opted to host it ourselves, and bought two 8-core servers with around a half-terabyte of disk space (RAIDed) and 24GB RAM to run Moodle from. One is the live server, with the other a hot spare. We've used lighttpd as the web server, FastCGI for running PHP, and xCache for PHP accelerator. We've stayed with MySQL for the database, although tables are using the InnoDB engine.
If anyone has any questions I can help answer, especially if you're thinking of doing a similar move, please do ask.
We're trying to encourage Moodle users here to start getting involved in the community, so hopefully you'll start seeing posts from St Andrews users in the next week or two.