I didn't even know brainstorm existed until I ran across it in an article on a techie-news website recently. I have been using various versions of Ubuntu/Xubuntu/Kubuntu since Dapper Drake was brand new.
There are a lot of people that know about the site already, but I think that we could get much more feedback if more users were aware of the site.
Maybe upon first time running firefox, konqueror, or what-have-you, an extra tab could open with links to things such as brainstorm, ubuntu help forums, etc. Much like firefox opens a new tab upon each update informing users of what's new, etc.
For starters Brainstorm needs more prominent links from the main Ubuntu.com website, which at present makes no mention of Brainstorm at all. Sometimes I just cant believe how inept things are relating to Ubuntu, can you imagine a proprietary software company not bothering to link to their new flagship community website from their main website?