I think Flex 3 Release version should have a new default theme for flex applications. Below is explanation, why.
Flex 3 is Really Better Than Flex 2, But It Should Be More Evident
I’m in love with Flex 3. Using it from beta to beta, I see how it becomes mature, and how Flex apps performance is growing. A lot of buzz will follow the Flex 3 Release, surely. And there’s a lot of people who saw the Flex 2 and will compare it with Flex 3. I guess a lot of them haven’t followed by the Flex 3 betas, being involved in tight development of their current Flex 2 projects. They expect to see something new and worthy of upgrade in the Flex 3 Release.
Now, they’re looking at the new Flex 3 samples. They’re seeing the coolness, but samples are visually equal to the Flex 2! So, the potential of the quick recognition of new Flex 3 features is decreased by it’s old Flex 2 default theme.
The Power of First Sight
It is all about people’s attention: when you see something familiar, but looking as new, you expect it to work as something new. And, from other hand, when you see something new, but looking too familiar at the first sight, you expect it to be not so new as it could be. Now: when Flex 2 developer looks at the Flex 3 apps with its default skin used, he still sees good old Flex 2 app. He realizes it is Flex 3, but he sees Flex 2. Cognitive conflict? Some say we get 80% of info through the eyes.
The less developers’ recognition of Flex 3 as really new one, the less experiments with Flex 3, the less buzz, the less community growth.
One More Reason: Flex 2 Default Skin is Just Too Old
More than year ago, Flex 2 was released. Two years have gone, but Flex apps default theme look exactly the same. However, graphic design trends aren’t something frozen. Flex RIAs, as cutting edge apps, should not look as they were two years ago. It’s just so… Web 1.9.9 
New Flex 3 Default Theme As a Part of Flex Microevangelism
Good news is that Adobe’s Evangelists already use the new Flex skins in their demos: for example, there’s cool black theme in BlazeBench by James Ward. The same theme is used in the Flex Builder 3 betas, look at welcome screen. Maybe Adobe’s preparing some cool design surprise for the community? I don’t know, but back to the “microevangelism”: I use this term to depict any Flex Evangelization which comes not from Adobe’s evangelists directly, but is spawned by the developers who can even don’t realize it. I mean: each Flex 3 developer putting his new cool Flex 3 application online unintentionally (or not) becomes the microevangelist, right? But: putting experiments online, developers usually don’t care much about their look and feel, functionality comes first, and it is as it should be with experiments. Developers rarely use the non-default skins in their experiments, so taking into account that there’s a huge quantity of simple flex samples made by developers, it is really important for Adobe to force the new look-and-feel of the new Flex 3 samples, which will be spawned over the web shortly after Flex 3 Release. Adobe, just color the seeds of flex and you’ll gather something more explosive than with old theme.
Is It Hard to Make New Default Theme for The Flex 3?
Flex has such powerful skinning mechanism, that there’s a lot of ready-to-use free cool Flex skins. But: if you’re Flex Developer and want to use cool skin, you must 1) Know where to get the skin 2) Download it 3) Apply it. Too many clicks for simple experiments. It seems to be not very hard for Adobe to ship Flex 3 with new default theme pre-installed, right?
Even more cool is the option for the developer to choose theme from the combo-box with 2-3 themes ready. Well, maybe it is hard to make new default theme now… but I dream of it!
Adobe, please don’t miss the opportunity to make greater impact on RIA with not very much of additional effort!