I think leaving the repository open with some behind the scenes code validation makes the most sense. I haven't seen a deliberately malicious plugin yet, and I have a feeling if it existed it would get pulled down pretty quickly.

I think the fundamental reason why WordPress has gained the popularity that it has, is because even a novice can join in and learn with the pros. Everyone is at a different stage of experience and knowledge, and there are bound to be flaws and bugs in just about every plugin out there when someone higher up the ladder looks down at it.

I agree that the "just because it works doesn't mean it's right" philosophy is one that as a developer you have to adopt fairly quickly, but not everyone has the resources to have their plugin combed through.

What I would hate to see is for the repo to follow the iPhone Store way of life and start rejecting or removing plugins. WordPress has always respected its legacy and the code it left behind, so if a stagnant plugin is sitting there and maybe needs some TLC, in our GPL open source world someone is free to pick up that lost code and give it a new home. If plugins were removed or rejected, that option disappears.

Imagine the kid that's submitting their first plugin to the repo, waiting anxiously to show their friends what they did, only they get an email two days later saying it was rejected. With that kind of setup, it breaks their spirits and maybe makes them stop trying. With the current setup, they submit their code to the repo and if people download it they can give feedback to the developer via the wp.org forums, so that kid can learn from their peers and grow to be a better developer.

If there's going to be a community of developers combing through plugin code looking for vulnerabilities or exploits, I hope it's a positive experience for everyone and it's treated like the customer service/public relations interaction that it is and that it happens pretty transparently.