In a discussion thread that states why to choose Laszlo over Macromedia Flex, this part is especially interesting:
"Laszlo is "future-proofed". It’s important to understand that the Laszlo solution today uses the Flash Player only as a rendering engine — and it was selected as a first target because it represents the most ubiquitous platform in the market today. However, the Laszlo development methodology is intentionally abstracted from Flash (i.e., a developer does not need to know anything about Flash authoring to build an LZX app), and because Laszlo will be supporting run-time environments other than the Flash Player in the future, your LZX applications will have a life and breadth beyond today’s Flash Player deployment platform.
While it’s highly unlikely that Macromedia will be supporting Flex deployment to other vendor platforms (such as Microsoft’s CLR, etc.), Laszlo intends on providing support for as many delivery choices as possible — meaning your existing LZX code can eventually be deployed on any number of present and future platforms, without the need to re-write applications, migrate code, or re-test functionality."
Pricing is also mentioned, since Lazlo so far lacks a realistic option for small businesses, let alone hobbyists.