Matt Woodward's Blog: "Laszlo Systems just announced that their RIA platform is now open source and free for deployment. I haven't checked out Laszlo in a while so I'll have to revisit this. Based on the little bit of playing around I did today I get the sense that Flex is still a more robust, capable solution, but this is GREAT news for the advancement of RIAs." (entry is old but links there are up-to-date)

Laszlo is looking very nice and it IS Open Source, more info : http://www.openlaszlo.org/

Peldi's Little Blog: Focus on usability!: " It seems that the more expensive the software is, the less usable it is. Horrible."

There's some good links bottom of the post. I have to keep eye on usability (when doing MY own Apps/Sites)