I would like to see a few more ASICs going live, and an updated client which addresses the blocksize limit first. By confidence as a Joe-average would rise then.
Purposely stressing things would see my holdings fall in value in the short term I think as people would panic sell.
Surely these things can be tested on a separate network though? It must be fairly easy to simulate scenarios such as a massive surge in transactions etc? I would download a test client to run a parallel blockchain and send play Bitcoins if it would help the community.