The first details of the overarching “themes” for Flex 4 (“Gumbo”) have been posted on the Flex open source wiki. Four themes are listed (“Design in Mind”, “Accelerated Development”, “Horizontal Platform Improvements”, and “Broadening Horizons”) although currently only ”Design in Mind” has any details.

And what nice details they are!

Here are a few highlights that stood out to me:

Flex applications however have gained a reputation for looking too similar to each other, as many developers choose to use the Flex default look and feel (known as Halo)…we have found that it remains too challenging to create a truly custom experience. It is therefore a priority for Gumbo to make easy customization of Flex application experiences the norm instead of the exception.

Major features…component and skinning architecture…make it easier to describe experience-oriented features such as states and transitions

Perhaps the most revealing part for existing Flex devs is the aptly named “Caveats and Reassurances” section:

Gumbo will remain compatible with Flex 3…Over multiple releases post-Gumbo we expect to deprecate the Halo model…Halo and new Gumbo components can co-exist…new MXML features may require some changes to your existing markup. However, you can make these decisions on a file-by-file basis

But my favorite line of all is in the “Related Work” section:

Provide a tool in which design-oriented users can easily customize the look of individual components or entire applications. Yes, this is Thermo. We’re not discussing it here.

Of course, this is all fairly in line with what’s been talked about previously, such as Thermo, MXML-G, Ely’s presentation about a new component structure with separation of model and view, etc. But it’s nice to see more information…and what’s not there but is hinted at is even more tantalizing.

I’ll definitely be watching that page for more information about “Design in Mind” and the other Flex 4 themes.

(via email from Matt Chotin – also see the announcement on the Flex team blog)