Good to know I didn't miss that much ;-)
I think the best strategy would be to create it as an organisational FOSS project. This way, someone else can set it up, so you won't be accountable regarding export regulations.
There are a lot of Tunnelblick-related and forked projects on GitHub, I'd suggest going over there.
I'm not sure if Google Code has a read-only mode, but that would make it easier to migrate: you could first migrate code and issues, and then everything else as needed. I'd be happy to help with that.
If you want to, I could setup a Tunnelblick organisation, import the code, and then add you as an owner/admin, that way, you will be more like a "contributor" and that should allow you to work on the project since you're not exporting anything.
As FOSS projects usually take off and get a lot of attention when they integrate more, I'd suspect that you'd get more code help and contributions when using such a service (as GitHub or Bitbucket, or even Codeplex).
Now, I'd like to help, but I'm not a Obj-C wizard in terms of Cocoa/Foundation etc. (but I'm getting there ;-) )
I do have a very good history with other parts of Tunnelblick such as OpenVPN itself, shell scripting, OSX network scripting etc. and regarding the artwork, I'd be happy to design/supply/edit things. I have the tools and the experience (and the network, I know a ton of designers that are happy to design an icon or something like that for an UI for free for example).
Would it be okay if I set up the GitHub thing anyway? I think the username is already taken but Tunnelblick.net or TunnelblickVPN are free I suppose. I don't know if you already have a GitHub account, if so, I could immediately add you.
Regarding export regulations in the US (I'm not a US citizen), do they apply if you contribute to an existing project in terms of code?