I'm playing around with RobotLegs today. Has anyone come across others? Any thoughts on them?
I haven't built anything from scratch with it yet, but have collab'ed on a couple of Gaia projects. I was impressed with it.
I've done a couple of projects in Gaia (one is featured in Gaia's gallery, in fact 
). All turned out less than ideal. Not that it isn't powerful - it certainly is - but I found myself spending more time adapting the projects to its needs than the other way around.
I'm sure that once one is comfortable it rocks - automatic HTML, SEO, and SWFAddress integration? awesome! - but I gave up.
Annnywho, with all of its automation it is far from mini!
yeah one of my colleagues said the same. I'll have to get around to building one entirely myself to really see if works for me or not.
So in a nutshell, what does robotlegs do for you then?
I think you inject the event logic for a flex app, it has a single bus you can tap into.
Its all a bit geeky and I am not convinced it seems to require rather a high level of knowledge and expertise, which to me makes it difficult to maintain and difficult to get dev's with enough expertise, seems like from a more simplistic viewpoint, you could use something like HSL (which is not EventDispatcher inheritance based) to shove all your events to a global/bus or busses, and then take them off there, most of these event frameworks are designed to work with flex. Seems robotlegs can be used with Gaia, aparently it is an improvement over something like MVC. I am yet to find any inspiring and prefer to do my own thing, but maybe I am just stiring to see what someone who uses them says.
Branden Hall and Joshua Davis: HYPE
that looks interesting, will have to check it out.
I guess in this vein is the marvellous TweenMax - I only recently started using it and I really regret not doing so a long time ago. I've always been reluctant to use these things, but this one really is a boon.
Ok, well I'm a bit late to the thread, but as you say JLM, "stirring" is what you've done 
I've used quite a few frameworks, and have also done a lot of my own things. Most recently, I've switched to RobotLegs and find it amazing - for me better than any of the others (though one shouldn't tie yourself into a single framework, sometimes different ones work better in different circumstances). The initial conceptual jump is a bit tough (your so-called threat of the need for a "high level of knowledge"), but once it clicks, it's amazingly simple - and I really do mean that. The only reason it might seem difficult is because it is unusual to regular approaches, but once you start to use it, it makes so much more sense and your projects are hugely easy to understand, incredibly easy to maintain, and very flexible and extensible.
PureMVC has been very good to me, and Mate was a bit of fun (though kinda weird), but unless you spend a lot of time developing your own comprehensive framework (does one really need to at this point?), I would advise against "doing your own thing". You inevitably lose time by rebuilding things over and over, and spending a lot of time trying to have your system communicate well with itself, where frameworks come with that logic built in, as well as separating the distinct tiers of your application automatically (ie., MVC, but only if you want it to - it is flexible enough to fit any architectural paradigm you like). And I don't like Gaia.