Wow, lots of energy here!
We love to see people developing products and standards around Arduino: it might help sell Arduino boards, but it also greatly increases the choices available to the community, which is more important. And, of course, we love to see other people building on and benefitting from our work; that's one of the main reasons it's an open-source project.
A standard around I2C shields would be wonderful. Does someone want to open a thread in the hardware development
forum to start hashing it out? The Arduino team would be happy to help create and support it.
We're also always interested in adding new products to Arduino - and, of course, sharing the profits from those products with their creators. We try to balance that with the desire to keep the core line small, so that beginners have an easy time getting started. If you have an idea, we'd love to hear about it and see if it makes sense to include - if not, we're happy to see it developed independently. If money is ever a problem, I'm sure we can find a way to help.
As for coordinating and discussing development: you're welcome to use the forums (e.g. the ones on hardware and software development), the playground (which is publicly editable), and the developers mailing list for discussion and coordination. I also just created an Arduino playground
project on Google Code that includes a Subversion repository. I'd like it to be publicly editable in the same way as the playground wiki, but I don't think Google Code supports that - so if you want access, just post your Google account username and I'll add you. We could set up more infrastructure, but I think we can accomplish a lot with a wiki, a forum, a mailing list, and a version control repository. If you've got other ideas, please throw them out there.
Again, it's great to see this kind of discussion, and I'm happy to do what I can to help.
That's a very positive sentiment Mellis, I'm sure everyone appreciates it in addition to the fine work you do already.
If Arduino added a shopping cart to it's site, that provided for multiple merchants allowing each to log-in and configure their own product, shipping costs and current inventories, then everyone could sell their products from the one location - including the guys from tinker.it
That way, anyone interested in buying Arduino/related products would have the one handy location to do all their shopping - and the sellers providing product and support, would never be too far away because they're all members at the forum.
At the moment, there are tiny e-commerce sites scattered all over the web selling Arduino/related product. It must be very confusing to new people trying to figure out their options. So if they can buy a whole bunch of product from one location, regardless of the location it's distributed from, then they might be inclined to buy more in a single transaction.