Usability is definitely a big issue for us all right now. We have all used better interfaces than Moodle offers, and I agree with basically all the detractors of our current interface. I've been thinking a lot about it.
I'd say there are two things we should approach here at the same time. In fact I've started putting them on the Roadmap recently.
- There is a lot of low-hanging fruit. Small easy-to-fix usability problems that really impact new users. These are the small specific issues that Tim mentions above. Stuff like better defaults for a new site, and less-cryptic names for things like the "HTML block". A major project for 2.3 will be identifying as many of these as possible and fixing them. I'll be posting more about this soon to gather info on people's "favourite" pain points (some of this has been happening already in past months, I've been observing new users with Moodle).
- We need to seriously look at the whole workflow of building and conducting and following courses. There's been a lot of good ideas about this over the years. We need to look at these and implement them in the medium-term, like 2.4. And yes, probably engage full-time usability experts to help.
Finally I should say that usability is really really REALLY hard to get right. A lot of so-called experts still produce interfaces that we (individually) may not like. Think of the outcry every time Facebook is updated, think of all the frustration you still experience even with the very latest stuff from Apple, think of the new 2.x quiz-editing interface in Moodle which, even though a usability person with training developed it by the book has ended up as something that I personally find completely non-intuitive and confusing.
Perfect interface design always has to cope with prior learning and technology constraints. All we can do is continue to strive to find a better balance.
One other thing I think we need to be mindful of is changing the Moodle paradigm too radically. Evolution not revolution. There are a lot of users who have invested a lot of time in learning how Moodle works, and we can't alienate them.